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Sample records for artificial chromosome libraries

  1. Bacterial Artificial Chromosome Libraries of Pulse Crops: Characteristics and Applications

    PubMed Central

    Yu, Kangfu

    2012-01-01

    Pulse crops are considered minor on a global scale despite their nutritional value for human consumption. Therefore, they are relatively less extensively studied in comparison with the major crops. The need to improve pulse crop production and quality will increase with the increasing global demand for food security and people's awareness of nutritious food. The improvement of pulse crops will require fully utilizing all their genetic resources. Bacterial artificial chromosome (BAC) libraries of pulse crops are essential genomic resources that have the potential to accelerate gene discovery and enhance molecular breeding in these crops. Here, we review the availability, characteristics, applications, and potential applications of the BAC libraries of pulse crops. PMID:21811383

  2. Construction and Characterization of Three Wheat Bacterial Artificial Chromosome Libraries

    PubMed Central

    Cao, Wenjin; Fu, Bisheng; Wu, Kun; Li, Na; Zhou, Yan; Gao, Zhongxia; Lin, Musen; Li, Guoqiang; Wu,  Xinyi; Ma, Zhengqiang; Jia, Haiyan

    2014-01-01

    We have constructed three bacterial artificial chromosome (BAC) libraries of wheat cultivar Triticum aestivum Wangshuibai, germplasms T. monococcum TA2026 and TA2033. A total of 1,233,792,170,880 and 263,040 clones were picked and arrayed in 384-well plates. On the basis of genome sizes of 16.8 Gb for hexaploid wheat and 5.6 Gb for diploid wheat, the three libraries represented 9.05-, 2.60-, and 3.71-fold coverage of the haploid genomes, respectively. An improved descending pooling system for BAC libraries screening was established. This improved strategy can save 80% of the time and 68% of polymerase chain reaction (PCR) with the same successful rate as the universal 6D pooling strategy. PMID:25464379

  3. Construction and characterization of three wheat bacterial artificial chromosome libraries.

    PubMed

    Cao, Wenjin; Fu, Bisheng; Wu, Kun; Li, Na; Zhou, Yan; Gao, Zhongxia; Lin, Musen; Li, Guoqiang; Wu, Xinyi; Ma, Zhengqiang; Jia, Haiyan

    2014-01-01

    We have constructed three bacterial artificial chromosome (BAC) libraries of wheat cultivar Triticum aestivum Wangshuibai, germplasms T. monococcum TA2026 and TA2033. A total of 1,233,792,170,880 and 263,040 clones were picked and arrayed in 384-well plates. On the basis of genome sizes of 16.8 Gb for hexaploid wheat and 5.6 Gb for diploid wheat, the three libraries represented 9.05-, 2.60-, and 3.71-fold coverage of the haploid genomes, respectively. An improved descending pooling system for BAC libraries screening was established. This improved strategy can save 80% of the time and 68% of polymerase chain reaction (PCR) with the same successful rate as the universal 6D pooling strategy. PMID:25464379

  4. Sex Chromosome Evolution in Amniotes: Applications for Bacterial Artificial Chromosome Libraries

    PubMed Central

    Janes, Daniel E.; Valenzuela, Nicole; Ezaz, Tariq; Amemiya, Chris; Edwards, Scott V.

    2011-01-01

    Variability among sex chromosome pairs in amniotes denotes a dynamic history. Since amniotes diverged from a common ancestor, their sex chromosome pairs and, more broadly, sex-determining mechanisms have changed reversibly and frequently. These changes have been studied and characterized through the use of many tools and experimental approaches but perhaps most effectively through applications for bacterial artificial chromosome (BAC) libraries. Individual BAC clones carry 100–200 kb of sequence from one individual of a target species that can be isolated by screening, mapped onto karyotypes, and sequenced. With these techniques, researchers have identified differences and similarities in sex chromosome content and organization across amniotes and have addressed hypotheses regarding the frequency and direction of past changes. Here, we review studies of sex chromosome evolution in amniotes and the ways in which the field of research has been affected by the advent of BAC libraries. PMID:20981143

  5. Recombination walking: Genetic selection of clones from pooled libraries of yeast artificial chromosomes by homologous recombination

    SciTech Connect

    Miller, A.M.; Savinelli, E.A.; Couture, S.M.; Hannigan, G.M.; Han, Z.; Selden, R.F.; Treco, D.A. )

    1993-09-01

    Recombination walking is based on the genetic selection of specific human clones from a yeast artificial chromosome (YAC) library by homologous recombination. The desired clone is selected from a pooled (unorderd) YAC library, eliminating labor-intensive steps typically used in organizing and maintaining ordered YAC libraries. Recombination walking represents an efficient approach to library screening and is well suited for chromosome-walking approaches to the isolation of genes associated with common diseases. 29 refs., 4 figs., 1 tab.

  6. Construction and characterization of a bacterial artificial chromosome library for hexaploid wheat line 92R137

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For map-based cloning of genes conferring important traits in the hexaploid wheat line 92R137, a bacterial artificial chromosome (BAC) library, including two sub libraries, was constructed using the genomic DNA of 92R137 digested with restriction enzymes HindIII and BamHI. The BAC library was compos...

  7. Preparation of high molecular weight gDNA and bacterial artificial chromosome (BAC) libraries in plants.

    PubMed

    Biradar, Siddanagouda S; Nie, Xiaojun; Feng, Kewei; Weining, Song

    2014-01-01

    Bacterial artificial chromosome (BAC) libraries are extremely valuable large-insert DNA libraries for physical mapping, positional cloning, comparative genomic analysis, complete genome sequencing, and evolutionary studies. Due to their stability and relative simplicity BAC libraries are most preferred over other approaches for cloning large genomic DNA fragments for large-insert libraries. Isolation of intact high molecular weight (HMW) DNA is a critical step underlying the success of large-insert genomic DNA library construction. It requires the isolation of purified nuclei, embedding them into LMP agarose plugs, restriction digestion of the plugs, and quite often size selection using PFGE and electro-elution of insert DNA. The construction of BAC libraries is complex and challenging for most molecular laboratories. To facilitate the construction of BAC libraries, we present a step-by-step protocol for isolation of HMW DNA and construction of plant BAC libraries. PMID:24243195

  8. Construction, characterization and FISH mapping of a bacterial artificial chromosome library of Chinese pangolin (Manis pentadactyla).

    PubMed

    Che, J; Wang, J; Su, W; Ye, J; Wang, Y; Nie, W; Yang, F

    2008-01-01

    Chinese pangolins as a representative species in the order Pholidota have highly specified morphological characters and occupy an important place in the mammalian phylogenetic tree. To obtain genomic data for this species, we have constructed a bacterial artificial chromosome (BAC) library of Chinese pangolin. The library contains 208,272 clones with an average insert size of 122.1 kb and represents approximately eight times the Chinese pangolin haploid genome (if we assume that the Chinese pangolins have a genome size similar to human). One hundred and twenty randomly-selected BAC clones were mapped onto Chinese pangolin chromosomes by fluorescence in situ hybridization (FISH), showing a largely unbiased chromosomal distribution. Several clones containing repetitive DNA and ribosomal DNA genes were also found. The BAC library and FISH mapped BAC clones are useful resources for comparative genomics and cytogenetics of mammals and in particular, the ongoing genome sequencing project of Chinese pangolins. PMID:18931486

  9. Construction and characterization of a human bacterial artificial chromosome library

    SciTech Connect

    Kim, Ung-Jin; Birren, B.W.; Slepak, T.

    1996-06-01

    We have constructed an arrayed human genomic BAC library with approximately 4X coverage that is represented by 96,000 BAC clones with average insert size of nearly 140 kb. A new BAC vector that allows color-based positive screening to identify transformants with inserts has increased BAC cloning efficiency. The library was gridded onto hybridization filters at high density for efficient identification of BAC clones by colony hybridization. The library was also formulated into characteristic DNA pools to allow for PCR screening of the library mainly by screening with more than 300 different landmarks that include cDNA, STSs, and cosmid clones. We describe methods for using BAC clones and discuss the implications for genome characterization, mapping, and sequencing. 25 refs., 5 figs., 1 tab.

  10. Construction of bacterial artificial chromosome libraries for Zhikong Scallop Chlamys farreri

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Zhang, Xiaojun; Scheuring, Chantel F.; Zhang, Hongbin; Li, Fuhua; Xiang, Jianhai

    2008-05-01

    Two Large-insert genomic bacterial artificial chromosome (BAC) libraries of Zhikong scallop Chlamys farreri were constructed to promote our genetic and genomic research. High-quality megabase-sized DNA was isolated from the adductor muscle of the scallop and partially digested by BamH I and Mbo I, respectively. The BamH I library consisted of 53 760 clones while the Mbo I library consisted of 7 680clones. Approximately 96 % of the clones in BamH I library contained nuclear DNA inserts in average size of 100 kb, providing a coverage of 5.3 haploid genome equivalents. Similarly, the Mbo I library with an average insert of 145 kb and no insert-empty clones, thus providing a genome coverage of 1.1 haploid genome equivalents.

  11. Construction and characterization of an eightfold redundant dog genomic bacterial artificial chromosome library.

    PubMed

    Li, R; Mignot, E; Faraco, J; Kadotani, H; Cantanese, J; Zhao, B; Lin, X; Hinton, L; Ostrander, E A; Patterson, D F; de Jong, P J

    1999-05-15

    A large insert canine genomic bacterial artificial chromosome (BAC) library was built from a Doberman pinscher. Approximately 166,000 clones were gridded on nine high-density hybridization filters. Insert analysis of randomly selected clones indicated a mean insert size of 155 kb and predicted 8.1 coverage of the canine genome. Two percent of the clones were nonrecombinant. Chromosomal fluorescence in situ hybridization studies of 60 BAC clones indicated no chimerism. The library was hybridized with dog PCR products representing eight genes (ADA, TNFA, GCA, MYB, HOXA, GUSB, THY1, and TOP1). The resulting positive clones were characterized and shown to be compatible with an eightfold redundant library. PMID:10331940

  12. Construction and characterization of a bacterial artificial chromosome library of Sorghum bicolor.

    PubMed Central

    Woo, S S; Jiang, J; Gill, B S; Paterson, A H; Wing, R A

    1994-01-01

    The construction of representative large insert DNA libraries is critical for the analysis of complex genomes. The predominant vector system for such work is the yeast artificial chromosome (YAC) system. Despite the success of YACs, many problems have been described including: chimerism, tedious steps in library construction and low yields of YAC insert DNA. Recently a new E.coli based system has been developed, the bacterial artificial chromosome (BAC) system, which offers many potential advantages over YACs. We tested the BAC system in plants by constructing an ordered 13,440 clone sorghum BAC library. The library has a combined average insert size, from single and double size selections, of 157 kb. Sorghum inserts of up to 315 kb were isolated and shown to be stable when grown for over 100 generations in liquid media. No chimeric clones were detected as determined by fluorescence in situ hybridization of ten BAC clones to metaphase and interphase S.bicolor nuclei. The library was screened with six sorghum probes and three maize probes and all but one sorghum probe hybridized to at least one BAC clone in the library. To facilitate chromosome walking with the BAC system, methods were developed to isolate the proximal ends of restriction fragments inserted into the BAC vector and used to isolate both the left and right ends of six randomly selected BAC clones. These results demonstrate that the S. bicolor BAC library will be useful for several physical mapping and map-based cloning applications not only in sorghum but other related cereal genomes, such as maize. Furthermore, we conclude that the BAC system is suitable for most large genome applications, is more 'user friendly' than the YAC system, and will likely lead to rapid progress in cloning biologically significant genes from plants. Images PMID:7800481

  13. A high-density physical map of Sinorhizobium meliloti 1021 chromosome derived from bacterial artificial chromosome library

    PubMed Central

    Capela, Delphine; Barloy-Hubler, Frédérique; Gatius, Marie-Thérèse; Gouzy, Jérôme; Galibert, Francis

    1999-01-01

    As part of the European Sinorhizobium meliloti (strain 1021) chromosome sequencing project, four genomic bacterial artificial chromosome (BAC) libraries have been constructed, one of which was mainly used for chromosome mapping. This library consists of 1,824 clones with an average insert size of 80 kilobases and represents approximately 20-fold total genome coverage [6.8 megabases (Mbs)]. PCR screening of 384 BAC clones with 447 chromosomal markers (PCR primer pairs), consisting of 73 markers representing 118 genes (40 individual genes and 78 genes clustered in 23 operons), two markers from the rrn operon (three loci), four markers from insertion sequences (≈16 loci) and 368 sequence-tagged sites allowed the identification of 252 chromosomal BAC clones and the construction of a high-density physical map of the whole 3.7-Mb chromosome of S. meliloti. An average of 5.5 overlapping and colinear BAC clones per marker, correlated with a low rate of deleted or rearranged clones (0.8%) indicate a solid BAC contigation and a correct mapping. Systematic blastx analysis of sequence-tagged site marker sequences allowed prediction of a biological function for a number of putative ORFs. Results are available at http://www-recomgen.univ-rennes1.fr/meliloti. This map, whose resolution averages one marker every 9 kilobases, should provide a valuable tool for further sequencing, functional analysis, and positional cloning. PMID:10430947

  14. Construction and characterization of a bacterial artificial chromosome library for the allotetraploid Gossypium tomentosum.

    PubMed

    Liu, F; Wang, Y H; Gao, H Y; Wang, C Y; Zhou, Z L; Cai, X Y; Wang, X X; Zhang, Z S; Wang, K B

    2015-01-01

    Gossypium tomentosum is a wild allotetraploid species with the (AD)5 genome. It is characterized by many useful traits including finer fiber fineness, drought tolerance, and Fusarium and Verticillium resistance. We constructed the first bacterial artificial chromosome library for Gossypium tomentosum. With high quality and broad coverage, this library includes 200,832 clones, with an average insert size of about 122 kb and fewer than 3% empty clones. Our library is approximately 10-fold the size of the (AD)5-genome (2400 Mb) and provides a 99.7% probability of isolating genes of interest or their sequences. Seven of eight simple sequence repeats markers that are located on five different chromosomes and linked with resistance to Verticillium wilt could amplify the 50 superpools and obtained one to five hits. This high capacity library will be an important genomic resource for classifying and analyzing the evolution of allotetraploid cotton species as well as for isolating disease-resistance and drought-tolerance genes. PMID:26681044

  15. Systematic screening of yeast artificial-chromosome libraries by use of the polymerase chain reaction.

    PubMed Central

    Green, E D; Olson, M V

    1990-01-01

    We have developed an approach for screening ordered arrays of yeast artificial-chromosome (YAC) clones containing human DNA that is based on the polymerase chain reaction (PCR). This approach is designed to determine the locations of positive clones within a YAC library that is stored as individual clones in 96-well microtiter plates. The high sensitivity and specificity of the PCR allow the detection of target sequences in DNA prepared from pools of 1920 or more YAC clones. The PCR-based screening protocol is performed in two successive stages, which effectively limit the location of a positive clone to four microtiter plates (384 clones). Final localization of each positive clone is accomplished by conventional DNA.DNA hybridization using a single filter containing the YAC clones from the appropriate four microtiter plates. This PCR-based screening strategy has proven highly efficient, allowing the identification and isolation of numerous YAC clones containing specific human genes. The prospects of developing a strategy for screening YAC libraries based completely on PCR assays are discussed, as are the potential applications of this approach to the systematic analysis of the human genome. Images PMID:2405397

  16. Mapping of low-frequency chimeric yeast artificial chromosome libraries from human chromosomes 16 and 21 by fluorescence in situ hybridization and quantitative image analysis

    SciTech Connect

    Marrone, B.L.; Campbell, E.W.; Anzick, S.L.; Shera, K.; Campbell, M.; Yoshida, T.M.; McCormick, M.K.; Deaven, L. )

    1994-05-01

    Yeast artificial chromosome (YAC) clones from low-frequency chimeric libraries of human chromosomes 16 and 21 were mapped onto human diploid fibroblast metaphase chromosomes using fluorescence in situ hybridization (FISH) and digital imaging microscopy. YACs mapped onto chromosome 21 were selected to provide subregional location and ordering of known and unknown markers on the long arm of chromosome 21, particularly in the Down syndrome region (q22). YACs mapped onto chromosome 16 were selected to overlap regions spanning chromosome 16 cosmid maps. YAC clones were indirectly labeled with fluorescein, and the total DNA of the chromosome was counterstained with propidium iodide. A single image containing both the FISH signal and the whole chromosome was acquired for each chromosome of interest containing the fluorescent probe signal in a metaphase spread. From the digitized image, the fluorescence intensity profile through the long axis of the chromosome gave the total chromosome length and the probe position. The map position of the probe was expressed as the fractional length (FL) of the total chromosome relative to the end of the short arm (Flpter). From each clone hybridized, 20-40 chromosome images were analyzed. Thirty-eight YACs were mapped onto chromosome 16, and their FLs were distributed along the short and long arms. On chromosome 21, 47 YACs were mapped, including 12 containing known markers. To confirm the order of a dense population of YACs within the Down syndrome region, a two-color mapping strategy was used in which an anonymous YAC was located relative to one or two known markers on the metaphase chromosome. The chromosome FL maps have a 1- to 2-Mb resolution, and the FL measurement of each probe has a typical standard error of 0.5-1 Mb. 14 refs., 3 figs., 3 tabs.

  17. Construction and targeted retrieval of specific clone from a non-gridded soybean bacterial artificial chromosome library.

    PubMed

    Xia, Zhengjun; Wu, Hongyan; Watanabe, Satoshi; Harada, Kyuya

    2014-01-01

    Although a post-genomic era is emerging for many plants, the bacterial artificial chromosome (BAC) library is still a valuable tool for genomic studies and preservation of precious genetic resources. Construction of non-gridded BAC libraries would dramatically reduce cost and save storage space. A non-gridded BAC library composed of approximately 96,000 insert-containing clones in 80 pools with an average insert size of 75 kb was constructed. This library represented 5.2 genome equivalents. We successfully developed a unique procedure to retrieve positive clones from the non-gridded pools. With this retrieving protocol, the non-gridded library system can be adapted to different species and to serve various research needs. PMID:24090869

  18. Construction and Analysis of Siberian Tiger Bacterial Artificial Chromosome Library with Approximately 6.5-Fold Genome Equivalent Coverage

    PubMed Central

    Liu, Changqing; Bai, Chunyu; Guo, Yu; Liu, Dan; Lu, Taofeng; Li, Xiangchen; Ma, Jianzhang; Ma, Yuehui; Guan, Weijun

    2014-01-01

    Bacterial artificial chromosome (BAC) libraries are extremely valuable for the genome-wide genetic dissection of complex organisms. The Siberian tiger, one of the most well-known wild primitive carnivores in China, is an endangered animal. In order to promote research on its genome, a high-redundancy BAC library of the Siberian tiger was constructed and characterized. The library is divided into two sub-libraries prepared from blood cells and two sub-libraries prepared from fibroblasts. This BAC library contains 153,600 individually archived clones; for PCR-based screening of the library, BACs were placed into 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 116.5 kb, representing approximately 6.46 genome equivalents of the haploid genome and affording a 98.86% statistical probability of obtaining at least one clone containing a unique DNA sequence. Screening the library with 19 microsatellite markers and a SRY sequence revealed that each of these markers were present in the library; the average number of positive clones per marker was 6.74 (range 2 to 12), consistent with 6.46 coverage of the tiger genome. Additionally, we identified 72 microsatellite markers that could potentially be used as genetic markers. This BAC library will serve as a valuable resource for physical mapping, comparative genomic study and large-scale genome sequencing in the tiger. PMID:24608928

  19. Construction and analysis of Siberian tiger bacterial artificial chromosome library with approximately 6.5-fold genome equivalent coverage.

    PubMed

    Liu, Changqing; Bai, Chunyu; Guo, Yu; Liu, Dan; Lu, Taofeng; Li, Xiangchen; Ma, Jianzhang; Ma, Yuehui; Guan, Weijun

    2014-01-01

    Bacterial artificial chromosome (BAC) libraries are extremely valuable for the genome-wide genetic dissection of complex organisms. The Siberian tiger, one of the most well-known wild primitive carnivores in China, is an endangered animal. In order to promote research on its genome, a high-redundancy BAC library of the Siberian tiger was constructed and characterized. The library is divided into two sub-libraries prepared from blood cells and two sub-libraries prepared from fibroblasts. This BAC library contains 153,600 individually archived clones; for PCR-based screening of the library, BACs were placed into 40 superpools of 10 × 384-deep well microplates. The average insert size of BAC clones was estimated to be 116.5 kb, representing approximately 6.46 genome equivalents of the haploid genome and affording a 98.86% statistical probability of obtaining at least one clone containing a unique DNA sequence. Screening the library with 19 microsatellite markers and a SRY sequence revealed that each of these markers were present in the library; the average number of positive clones per marker was 6.74 (range 2 to 12), consistent with 6.46 coverage of the tiger genome. Additionally, we identified 72 microsatellite markers that could potentially be used as genetic markers. This BAC library will serve as a valuable resource for physical mapping, comparative genomic study and large-scale genome sequencing in the tiger. PMID:24608928

  20. A chromosome 11 YAC library

    SciTech Connect

    Qin, S.; Zhang, J.; Isaacs, C.M.; Nagafuchi, S.; Jani Sait, S.N.; Abel, K.J.; Higgins, M.J.; Nowak, N.J.; Shows, T.B. )

    1993-06-01

    A targeted yeast artificial chromosome (YAC) library for chromosome 11 has been constructed from the J1 cell line that carries a single human chromosome 11 within a hamster DNA background. Interspecies chimeric clones generated during construction of the library were detected during the screening process and eliminated from the library. Contig assembly becomes much less difficult using such a library as the complexity is decreased and the ends of the clone inserts can be rescued for walking to neighboring clones. The library contains > 1824 clones with an average insert length of 337 kb. This represents a fourfold coverage of chromosome 11 or a >95% chance of recovering a unique single-copy sequence from the library. Two hundred YAC clones were localized by fluorescence in situ hybridization and found to be randomly distributed along the chromosome. The library has been screened with probes for the chromosome 11 markers HBB, GLUR4, H19, and D11S193. Corresponding YAC clones have been isolated for each locus. This analysis has indicated that the library is unbiased, that cognate YAC clones can be recovered with chromosome 11 markers, and that extensive contig assembly should be feasible. 31 refs., 5 figs.

  1. Construction and characterization of a 10-genome equivalent yeast artificial chromosome library for the laboratory rat, Rattus norvegicus

    SciTech Connect

    Cai, L.; Zee, R.Y.L.; Schalkwyk, L.C.

    1997-02-01

    Increasing attention has been focused in recent years on the rat as a model organism for genetic studies, in particular for the investigation of complex traits, but progress has been limited by the lack of availability of large-insert genomic libraries. Here, we report the construction and characterization of an arrayed yeast artificial chromosome (YAC) library for the rat genome containing approximately 40,000 clones in the AB1380 host using the pCGS966 vector. An average size of 736 kb was estimated from 166 randomly chosen clones; thus the library provides 10-fold coverage of the genome, with a 99.99% probability of containing a unique sequence. Eight of 39 YACs analyzed by fluorescence in situ hybridization were found to be chimeric, indicating a proportion of about 20-30% of chimeric clones. The library was spotted on high-density filters to allow the identification of YAC clones by hybridization and was pooled using a 3-dimensional scheme for screening by PCR. Among 48 probes used to screen the library, an average of 9.3 positive clones were found, consistent with the calculated 10-fold genomic coverage of the library. This YAC library represents the first large-insert genomic library for the rat. It will be made available to the research community at large as an important new resource for complex genome analysis in this species. 35 refs., 4 figs.

  2. Final report. Human artificial episomal chromosome (HAEC) for building large genomic libraries

    SciTech Connect

    Jean-Michael H. Vos

    1999-12-09

    Collections of human DNA fragments are maintained for research purposes as clones in bacterial host cells. However for unknown reasons, some regions of the human genome appear to be unclonable or unstable in bacteria. Their team has developed a system using episomes (extrachromosomal, autonomously replication DNA) that maintains large DNA fragments in human cells. This human artificial episomal chromosomal (HAEC) system may prove useful for coverage of these especially difficult regions. In the broader biomedical community, the HAEC system also shows promise for use in functional genomics and gene therapy. Recent improvements to the HAEC system and its application to mapping, sequencing, and functionally studying human and mouse DNA are summarized. Mapping and sequencing the human genome and model organisms are only the first steps in determining the function of various genetic units critical for gene regulation, DNA replication, chromatin packaging, chromosomal stability, and chromatid segregation. Such studies will require the ability to transfer and manipulate entire functional units into mammalian cells.

  3. Construction of a bacterial artificial chromosome library from the spikemoss Selaginella moellendorffii: a new resource for plant comparative genomics

    PubMed Central

    Wang, Wenming; Tanurdzic, Milos; Luo, Meizhong; Sisneros, Nicholas; Kim, Hye Ran; Weng, Jing-Ke; Kudrna, Dave; Mueller, Christopher; Arumuganathan, K; Carlson, John; Chapple, Clint; de Pamphilis, Claude; Mandoli, Dina; Tomkins, Jeff; Wing, Rod A; Banks, Jo Ann

    2005-01-01

    Background The lycophytes are an ancient lineage of vascular plants that diverged from the seed plant lineage about 400 Myr ago. Although the lycophytes occupy an important phylogenetic position for understanding the evolution of plants and their genomes, no genomic resources exist for this group of plants. Results Here we describe the construction of a large-insert bacterial artificial chromosome (BAC) library from the lycophyte Selaginella moellendorffii. Based on cell flow cytometry, this species has the smallest genome size among the different lycophytes tested, including Huperzia lucidula, Diphaiastrum digita, Isoetes engelmanii and S. kraussiana. The arrayed BAC library consists of 9126 clones; the average insert size is estimated to be 122 kb. Inserts of chloroplast origin account for 2.3% of the clones. The BAC library contains an estimated ten genome-equivalents based on DNA hybridizations using five single-copy and two duplicated S. moellendorffii genes as probes. Conclusion The S. moellenforffii BAC library, the first to be constructed from a lycophyte, will be useful to the scientific community as a resource for comparative plant genomics and evolution. PMID:15955246

  4. Construction and Characterization of a Bacterial Artificial Chromosome Library for the Hexaploid Wheat Line 92R137

    PubMed Central

    Yuan, Fengping; Xu, Xin; Shi, Xue; Zhuang, Hua; Wang, Zhonghua; Huang, Lili; Han, Dejun; Kang, Zhensheng

    2014-01-01

    For map-based cloning of genes conferring important traits in the hexaploid wheat line 92R137, a bacterial artificial chromosome (BAC) library, including two sublibraries, was constructed using the genomic DNA of 92R137 digested with restriction enzymes HindIII and BamHI. The BAC library was composed of total 765,696 clones, of which 390,144 were from the HindIII digestion and 375,552 from the BamHI digestion. Through pulsed-field gel electrophoresis (PFGE) analysis of 453 clones randomly selected from the HindIII sublibrary and 573 clones from the BamHI sublibrary, the average insert sizes were estimated as 129 and 113 kb, respectively. Thus, the HindIII sublibrary was estimated to have a 3.01-fold coverage and the BamHI sublibrary a 2.53-fold coverage based on the estimated hexaploid wheat genome size of 16,700 Mb. The 765,696 clones were arrayed in 1,994 384-well plates. All clones were also arranged into plate pools and further arranged into 5-dimensional (5D) pools. The probability of identifying a clone corresponding to any wheat DNA sequence (such as gene Yr26 for stripe rust resistance) from the library was estimated to be more than 99.6%. Through polymerase chain reaction screening the 5D pools with Xwe173, a marker tightly linked to Yr26, six BAC clones were successfully obtained. These results demonstrate that the BAC library is a valuable genomic resource for positional cloning of Yr26 and other genes of interest. PMID:24895618

  5. Construction of a high-coverage bacterial artificial chromosome library and comprehensive genetic linkage map of yellowtail Seriola quinqueradiata

    PubMed Central

    2014-01-01

    Background Japanese amberjack/yellowtail (Seriola quinqueradiata) is a commonly cultured marine fish in Japan. For cost effective fish production, a breeding program that increases commercially important traits is one of the major solutions. In selective breeding, information of genetic markers is useful and sufficient to identify individuals carrying advantageous traits but if the aim is to determine the genetic basis of the trait, large insert genomic DNA libraries are essential. In this study, toward prospective understanding of genetic basis of several economically important traits, we constructed a high-coverage bacterial artificial chromosome (BAC) library, obtained sequences from the BAC-end, and constructed comprehensive female and male linkage maps of yellowtail using Simple Sequence Repeat (SSR) markers developed from the BAC-end sequences and a yellowtail genomic library. Results The total insert length of the BAC library we constructed here was estimated to be approximately 11 Gb and hence 16-times larger than the yellowtail genome. Sequencing of the BAC-ends showed a low fraction of repetitive sequences comparable to that in Tetraodon and fugu. A total of 837 SSR markers developed here were distributed among 24 linkage groups spanning 1,026.70 and 1,057.83 cM with an average interval of 4.96 and 4.32 cM in female and male map respectively without any segregation distortion. Oxford grids suggested conserved synteny between yellowtail and stickleback. Conclusions In addition to characteristics of yellowtail genome such as low repetitive sequences and conserved synteny with stickleback, our genomic and genetic resources constructed and revealed here will be powerful tools for the yellowtail breeding program and also for studies regarding the genetic basis of traits. PMID:24684753

  6. Construction and characterization of a bacterial artificial chromosome library for the hexaploid wheat line 92R137.

    PubMed

    Zeng, Qingdong; Yuan, Fengping; Xu, Xin; Shi, Xue; Nie, Xiaojun; Zhuang, Hua; Chen, Xianming; Wang, Zhonghua; Wang, Xiaojie; Huang, Lili; Han, Dejun; Kang, Zhensheng

    2014-01-01

    For map-based cloning of genes conferring important traits in the hexaploid wheat line 92R137, a bacterial artificial chromosome (BAC) library, including two sublibraries, was constructed using the genomic DNA of 92R137 digested with restriction enzymes HindIII and BamHI. The BAC library was composed of total 765,696 clones, of which 390,144 were from the HindIII digestion and 375,552 from the BamHI digestion. Through pulsed-field gel electrophoresis (PFGE) analysis of 453 clones randomly selected from the HindIII sublibrary and 573 clones from the BamHI sublibrary, the average insert sizes were estimated as 129 and 113 kb, respectively. Thus, the HindIII sublibrary was estimated to have a 3.01-fold coverage and the BamHI sublibrary a 2.53-fold coverage based on the estimated hexaploid wheat genome size of 16,700 Mb. The 765,696 clones were arrayed in 1,994 384-well plates. All clones were also arranged into plate pools and further arranged into 5-dimensional (5D) pools. The probability of identifying a clone corresponding to any wheat DNA sequence (such as gene Yr26 for stripe rust resistance) from the library was estimated to be more than 99.6%. Through polymerase chain reaction screening the 5D pools with Xwe173, a marker tightly linked to Yr26, six BAC clones were successfully obtained. These results demonstrate that the BAC library is a valuable genomic resource for positional cloning of Yr26 and other genes of interest. PMID:24895618

  7. BACTERIAL ARTIFICIAL CHROMOSOME(BAC)LIBRARIES CONSTRUCTED FROM THE GENETIC STANDARD OF UPLAND COTTON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two BAC libraries and one plant transformation-competent BIBAC library were developed from the Gossypium hirsutum acc. TM-1 for the development of an integrative cotton physical and genetic map and other genomic applications. TM-1 is the most desirable choice for the physical map of Upland cotton be...

  8. [Construction and analysis of rumen bacterial artificial chromosome library from a dairy cow rumen microflora].

    PubMed

    Zhu, Ya-xin; Wang, Jia-qi; Ma, Run-lin; Huang, Li; Dong, Zhi-yang

    2007-04-01

    The high molecular weight DNA was extracted and purified directly from rumen samples in the study by using culture-independent and pulsed field gel electrophoresis approaches. After digestion with Hind III, DNA fragments ranging from 50-100 kb was collected and ligated to pCC BAC vector. The ligation mixture was transformed into E. coli EPI300 and a rumen metagenomic BAC library with about 15360 clones was constructed. The average insert size is about 54.5 kb, mostly ranging from 50-70 kb, and the capacity of this BAC library is about 837Mb. Several BAC clones with activity of amylase, Cmcellulase had been screened from the BAC library. The clones with Cmcelluase activity were screened further for linchenase, xylanase, cellobioase activity and the result is that 25 of them have at least one kind of other enzyme activity. PMID:17552222

  9. Construction of bacterial artificial chromosome libraries from the parasitic nematode Brugia malayi and physical mapping of the genome of its Wolbachia endosymbiont.

    PubMed

    Foster, Jeremy M; Kumar, Sanjay; Ganatra, Mehul B; Kamal, Ibrahim H; Ware, Jennifer; Ingram, Jessica; Pope-Chappell, Jesse; Guiliano, David; Whitton, Claire; Daub, Jennifer; Blaxter, Mark L; Slatko, Barton E

    2004-05-01

    The parasitic nematode, Brugia malayi, causes lymphatic filariasis in humans, which in severe cases leads to the condition known as elephantiasis. The parasite contains an endosymbiotic alpha-proteobacterium of the genus Wolbachia that is required for normal worm development and fecundity and is also implicated in the pathology associated with infections by these filarial nematodes. Bacterial artificial chromosome libraries were constructed from B. malayi DNA and provide over 11-fold coverage of the nematode genome. Wolbachia genomic fragments were simultaneously cloned into the libraries giving over 5-fold coverage of the 1.1 Mb bacterial genome. A physical framework for the Wolbachia genome was developed by construction of a plasmid library enriched for Wolbachia DNA as a source of sequences to hybridise to high-density bacterial artificial chromosome colony filters. Bacterial artificial chromosome end sequencing provided additional Wolbachia probe sequences to facilitate assembly of a contig that spanned the entire genome. The Wolbachia sequences provided a marker approximately every 10 kb. Four rare-cutting restriction endonucleases were used to restriction map the genome to a resolution of approximately 60 kb and demonstrate concordance between the bacterial artificial chromosome clones and native Wolbachia genomic DNA. Comparison of Wolbachia sequences to public databases using BLAST algorithms under stringent conditions allowed confident prediction of 69 Wolbachia peptide functions and two rRNA genes. Comparison to closely related complete genomes revealed that while most sequences had orthologs in the genome of the Wolbachia endosymbiont from Drosophila melanogaster, there was no evidence for long-range synteny. Rather, there were a few cases of short-range conservation of gene order extending over regions of less than 10 kb. The molecular scaffold produced for the genome of the Wolbachia from B. malayi forms the basis of a genomic sequencing effort for

  10. Repetitive genome elements in a European corn borer, Ostrinia nubilalis, bacterial artificial chromosome library were indicated by bacterial artificial chromosome end sequencing and development of sequence tag site markers: implications for lepidopteran genomic research.

    PubMed

    Coates, Brad S; Sumerford, Douglas V; Hellmich, Richard L; Lewis, Leslie C

    2009-01-01

    The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia and a model system for insect olfaction and speciation. A bacterial artificial chromosome library constructed for O. nubilalis contains 36 864 clones with an estimated average insert size of >or=120 kb and genome coverage of 8.8-fold. Screening OnB1 clones comprising approximately 2.76 genome equivalents determined the physical position of 24 sequence tag site markers, including markers linked to ecologically important and Bacillus thuringiensis toxin resistance traits. OnB1 bacterial artificial chromosome end sequence reads (GenBank dbGSS accessions ET217010 to ET217273) showed homology to annotated genes or expressed sequence tags and identified repetitive genome elements, O. nubilalis miniature subterminal inverted repeat transposable elements (OnMITE01 and OnMITE02), and ezi-like long interspersed nuclear elements. Mobility of OnMITE01 was demonstrated by the presence or absence in O. nubilalis of introns at two different loci. A (GTCT)n tetranucleotide repeat at the 5' ends of OnMITE01 and OnMITE02 are evidence for transposon-mediated movement of lepidopteran microsatellite loci. The number of repetitive elements in lepidopteran genomes will affect genome assembly and marker development. Single-locus sequence tag site markers described here have downstream application for integration within linkage maps and comparative genomic studies. PMID:19132072

  11. Amplification of large artificial chromosomes.

    PubMed Central

    Smith, D R; Smyth, A P; Moir, D T

    1990-01-01

    Yeast artificial chromosome cloning is an attractive technology for genomic mapping studies because very large DNA segments can be readily propagated. However, detailed analyses often require the extensive application of blotting-hybridization techniques because artificial chromosomes are normally present at only one copy per haploid genome. We have developed a cloning vector and host strain that alleviate this problem by permitting copy number amplification of artificial chromosomes. The vector includes a conditional centromere that can be turned on or off by changing the carbon source. Strong selective pressure for extra copies of the artificial chromosome can be applied by selecting for the expression of a heterologous thymidine kinase gene. When this system was used, artificial chromosomes ranging from about 100 to 600 kilobases in size were readily amplified 10- to 20-fold. The selective conditions did not induce obvious rearrangements in any of the clones tested. Reactivation of the centromere in amplified artificial chromosome clones resulted in stable maintenance of an elevated copy number for 20 generations. Applications of copy number control to various aspects of artificial chromosome analysis are addressed. Images PMID:2236036

  12. Construction and characterization of a bacterial artificial chromosome library of the causal agent of Black Sigatoka fungal leaf spot disease of banana and plantain, Mycosphaerella fijiensis.

    PubMed

    Canto-Canché, Blondy; Guillén-Maldonado, Diana Karina; Peraza-Echeverría, Leticia; Conde-Ferráez, Laura; James-Kay, Andrew

    2007-05-01

    A bacterial artificial chromosome library of the causal agent of the Black Sigatoka leaf spot disease of banana and plantain, Mycosphaerella fijiensis, has been constructed using a non-sphaeroplasting technique and characterized using both homologous and heterologous probes. After first and a second size selection of PFGE-fractionated DNA, a ligation was obtained using a 1:4 molar ratio (insert:vector). One hundred random clones were analyzed, and the mean insert size was estimated to be 90 kb. The range of the insert sizes was between 40 and 160 kb. The highest percentage of inserts belonged to the range between 80 and 100 kb; 32% of the inserts had 2 or 3 internal NotI sites. This library consists of 1920 clones, if the genomic size is at least 35 Mb, then this represents 4.9 x genome equivalents, which was supported by hybridization results with homologous and heterologous probes. PMID:17827540

  13. Analysis of chromosome 21 yeast artificial chromosome (YAC) clones

    SciTech Connect

    Tassone, F. A. Gemelli School of Medicine, Rome ); Cheng, S.; Gardiner, K. )

    1992-12-01

    Chromosome 21 contains genes relevant to several important diseases. Yeast artificial chromosome (YAC) clones, because they span >100 kbp, will provide attractive material for initiating searches for such genes. Twenty-two YAC clones, each of which maps to a region of potential relevance either to aspects of the Down syndrome phenotype or to one of the other chromosome 21-associated genetic diseases, have been analyzed in detail. Clones total [approximately]6,000 kb and derive from all parts of the long arm. Rare restriction-site maps have been constructed for each clone and have been used to determine regional variations in clonability, methylation frequency, CpG island density, and CpG island frequency versus gene density. This information will be useful for the isolation and mapping of new genes to chromosome 21 and for walking in YAC libraries. 48 refs., 3 figs., 4 tabs.

  14. A bacterial artificial chromosome library for the Australian saltwater crocodile (Crocodylus porosus) and its utilization in gene isolation and genome characterization

    PubMed Central

    2009-01-01

    Background Crocodilians (Order Crocodylia) are an ancient vertebrate group of tremendous ecological, social, and evolutionary importance. They are the only extant reptilian members of Archosauria, a monophyletic group that also includes birds, dinosaurs, and pterosaurs. Consequently, crocodilian genomes represent a gateway through which the molecular evolution of avian lineages can be explored. To facilitate comparative genomics within Crocodylia and between crocodilians and other archosaurs, we have constructed a bacterial artificial chromosome (BAC) library for the Australian saltwater crocodile, Crocodylus porosus. This is the first BAC library for a crocodile and only the second BAC resource for a crocodilian. Results The C. porosus BAC library consists of 101,760 individually archived clones stored in 384-well microtiter plates. NotI digestion of random clones indicates an average insert size of 102 kb. Based on a genome size estimate of 2778 Mb, the library affords 3.7 fold (3.7×) coverage of the C. porosus genome. To investigate the utility of the library in studying sequence distribution, probes derived from CR1a and CR1b, two crocodilian CR1-like retrotransposon subfamilies, were hybridized to C. porosus macroarrays. The results indicate that there are a minimum of 20,000 CR1a/b elements in C. porosus and that their distribution throughout the genome is decidedly non-random. To demonstrate the utility of the library in gene isolation, we probed the C. porosus macroarrays with an overgo designed from a C-mos (oocyte maturation factor) partial cDNA. A BAC containing C-mos was identified and the C-mos locus was sequenced. Nucleotide and amino acid sequence alignment of the C. porosus C-mos coding sequence with avian and reptilian C-mos orthologs reveals greater sequence similarity between C. porosus and birds (specifically chicken and zebra finch) than between C. porosus and squamates (green anole). Conclusion We have demonstrated the utility of the

  15. Construction, Analysis, and β-Glucanase Screening of a Bacterial Artificial Chromosome Library from the Large-Bowel Microbiota of Mice†

    PubMed Central

    Walter, Jens; Mangold, Marco; Tannock, Gerald W.

    2005-01-01

    A metagenomic (community genomic) library consisting of 5,760 bacterial artificial chromosome clones was prepared in Escherichia coli DH10B from DNA extracted from the large-bowel microbiota of BALB/c mice. DNA inserts detected in 61 randomly chosen clones averaged 55 kbp (range, 8 to 150 kbp) in size. A functional screen of the library for β-glucanase activity was conducted using lichenin agar plates and Congo red solution. Three clones with β-glucanase activity were detected. The inserts of these three clones were sequenced and annotated. Open reading frames (ORF) that encoded putative proteins with identity to glucanolytic enzymes (lichenases and laminarinases) were detected by reference to databases. Other putative genes were detected, some of which might have a role in environmental sensing, nutrient acquisition, or coaggregation. The insert DNA from two clones probably originated from uncultivated bacteria because the ORF had low sequence identity with database entries, but the genes associated with the remaining clone resembled sequences reported in Bacteroides species. PMID:15870321

  16. Construction of BAC Libraries from Flow-Sorted Chromosomes.

    PubMed

    Šafář, Jan; Šimková, Hana; Doležel, Jaroslav

    2016-01-01

    Cloned DNA libraries in bacterial artificial chromosome (BAC) are the most widely used form of large-insert DNA libraries. BAC libraries are typically represented by ordered clones derived from genomic DNA of a particular organism. In the case of large eukaryotic genomes, whole-genome libraries consist of a hundred thousand to a million clones, which make their handling and screening a daunting task. The labor and cost of working with whole-genome libraries can be greatly reduced by constructing a library derived from a smaller part of the genome. Here we describe construction of BAC libraries from mitotic chromosomes purified by flow cytometric sorting. Chromosome-specific BAC libraries facilitate positional gene cloning, physical mapping, and sequencing in complex plant genomes. PMID:27511172

  17. Pure chromosome-specific PCR libraries from single sorted chromosomes.

    PubMed Central

    VanDevanter, D R; Choongkittaworn, N M; Dyer, K A; Aten, J; Otto, P; Behler, C; Bryant, E M; Rabinovitch, P S

    1994-01-01

    Chromosome-specific DNA libraries can be very useful in molecular and cytogenetic genome mapping studies. We have developed a rapid and simple method for the generation of chromosome-specific DNA sequences that relies on polymerase chain reaction (PCR) amplification of a single flow-sorted chromosome or chromosome fragment. Previously reported methods for the development of chromosome libraries require larger numbers of chromosomes, with preparation of pure chromosomes sorted by flow cytometry, generation of somatic cell hybrids containing targeted chromosomes, or a combination of both procedures. These procedures are labor intensive, especially when hybrid cell lines are not already available, and this has limited the generation of chromosome-specific DNA libraries from nonhuman species. In contrast, a single sorted chromosome is a pure source of DNA for library production even when flow cytometric resolution of chromosome populations is poor. Furthermore, any sorting cytometer may be used with this technique. Using this approach, we demonstrate the generation of PCR libraries suitable for both molecular and fluorescence in situ hybridization studies from individual baboon and canine chromosomes, separate human homologues, and a rearranged marker chromosome from a transformed cell line. PCR libraries specific to subchromosomal regions have also been produced by sorting a small chromosome fragment. This simple and rapid technique will allow generation of nonhuman linkage maps and probes for fluorescence in situ hybridization and the characterization of marker chromosomes from solid tumors. In addition, allele-specific libraries generated by this strategy may also be useful for mapping genetic diseases. Images PMID:8016078

  18. Selection of chromosome 22-specific clones from human genomic BAC library using a chromosome-specific cosmid library pool

    SciTech Connect

    Kim, U.J.; Shizuya, H.; Birren, B.

    1994-07-15

    A new approach to rapidly identify chromosome-specific subsets of clones from a total human genomic library is described. The authors report here the results of screening a human bacterial artificial chromosome (BAC) library using the total pool of clones from a chromosome 22-specific cosmid library as a composite probe. The human BAC library was gridded on filters at high density and hybridized with DNA from the pooled chromosome 22-specific Lawrist library under suppressive conditions. In a single hybridization, they picked 280 candidates from the BAC library representing over 30,000 clones (or 1.2 x coverage of human genome). This subset contained more than 60% of the chromosome 22-specific BAC clones that were previously found to be present in the original BAC library. In principle, this approach can be applied to select a subset of clones from other global libraries with relatively large inserts using a pool from a regional library as a composite probe. It is important to note that the target and probe libraries must be based on vectors that share no homology with each other. 8 refs., 2 figs., 2 tabs.

  19. Generation of a complete single-gene knockout bacterial artificial chromosome library of cowpox virus and identification of its essential genes.

    PubMed

    Xu, Zhiyong; Zikos, Dimitrios; Osterrieder, Nikolaus; Tischer, B Karsten

    2014-01-01

    Cowpox virus (CPXV) belongs to the genus Orthopoxvirus in the Poxviridae family. It infects a broad range of vertebrates and can cause zoonotic infections. CPXV has the largest genome among the orthopoxviruses and is therefore considered to have the most complete set of genes of all members of the genus. Since CPXV has also become a model for studying poxvirus genetics and pathogenesis, we created and characterized a complete set of single gene knockout bacterial artificial chromosome (BAC) clones of the CPXV strain Brighton Red. These mutants allow a systematic assessment of the contribution of single CPXV genes to the outcome of virus infection and replication, as well as to the virus host range. A full-length BAC clone of CPXV strain Brighton Red (pBRF) harboring the gene expressing the enhanced green fluorescent protein under the control of a viral late promoter was modified by introducing the mrfp1 gene encoding the monomeric red fluorescent protein driven by a synthetic early vaccinia virus promoter. Based on the modified BAC (pBRFseR), a library of targeted knockout mutants for each single viral open reading frame (ORF) was generated. Reconstitution of infectious virus was successful for 109 of the 183 mutant BAC clones, indicating that the deleted genes are not essential for virus replication. In contrast, 74 ORFs were identified as essential because no virus progeny was obtained upon transfection of the mutant BAC clones and in the presence of a helper virus. More than 70% of all late CPXV genes belonged to this latter group of essential genes. PMID:24155400

  20. Chromosome region-specific libraries for human genome analysis

    SciTech Connect

    Kao, Fa-Ten.

    1992-08-01

    During the grant period progress has been made in the successful demonstration of regional mapping of microclones derived from microdissection libraries; successful demonstration of the feasibility of converting microclones with short inserts into yeast artificial chromosome clones with very large inserts for high resolution physical mapping of the dissected region; Successful demonstration of the usefulness of region-specific microclones to isolate region-specific cDNA clones as candidate genes to facilitate search for the crucial genes underlying genetic diseases assigned to the dissected region; and the successful construction of four region-specific microdissection libraries for human chromosome 2, including 2q35-q37, 2q33-q35, 2p23-p25 and 2p2l-p23. The 2q35-q37 library has been characterized in detail. The characterization of the other three libraries is in progress. These region-specific microdissection libraries and the unique sequence microclones derived from the libraries will be valuable resources for investigators engaged in high resolution physical mapping and isolation of disease-related genes residing in these chromosomal regions.

  1. Screening of an E. coli O157:H7 Bacterial Artificial Chromosome Library by Comparative Genomic Hybridization to Identify Genomic Regions Contributing to Growth in Bovine Gastrointestinal Mucus and Epithelial Cell Colonization

    PubMed Central

    Bai, Jianing; McAteer, Sean P.; Paxton, Edith; Mahajan, Arvind; Gally, David L.; Tree, Jai J.

    2011-01-01

    Enterohemorrhagic E. coli (EHEC) O157:H7 can cause serious gastrointestinal and systemic disease in humans following direct or indirect exposure to ruminant feces containing the bacterium. The main colonization site of EHEC O157:H7 in cattle is the terminal rectum where the bacteria intimately attach to the epithelium and multiply in the intestinal mucus. This study aimed to identify genomic regions of EHEC O157:H7 that contribute to colonization and multiplication at this site. A bacterial artificial chromosome (BAC) library was generated from a derivative of the sequenced E. coli O157:H7 Sakai strain. The library contains 1152 clones averaging 150 kbp. To verify the library, clones containing a complete locus of enterocyte effacement (LEE) were identified by DNA hybridization. In line with a previous report, these did not confer a type III secretion (T3S) capacity to the K-12 host strain. However, conjugation of one of the BAC clones into a strain containing a partial LEE deletion restored T3S. Three hundred eighty-four clones from the library were subjected to two different selective screens; one involved three rounds of adherence assays to bovine primary rectal epithelial cells while the other competed the clones over three rounds of growth in bovine rectal mucus. The input strain DNA was then compared with the selected strains using comparative genomic hybridization (CGH) on an E. coli microarray. The adherence assay enriched for pO157 DNA indicating the importance of this plasmid for colonization of rectal epithelial cells. The mucus assay enriched for multiple regions involved in carbohydrate utilization, including hexuronate uptake, indicating that these regions provide a competitive growth advantage in bovine mucus. This BAC-CGH approach provides a positive selection screen that complements negative selection transposon-based screens. As demonstrated, this may be of particular use for identifying genes with redundant functions such as adhesion and carbon

  2. Development of genomic resources for the narrow-leafed lupin (Lupinus angustifolius): construction of a bacterial artificial chromosome (BAC) library and BAC-end sequencing

    PubMed Central

    2011-01-01

    Background Lupinus angustifolius L, also known as narrow-leafed lupin (NLL), is becoming an important grain legume crop that is valuable for sustainable farming and is becoming recognised as a potential human health food. Recent interest is being directed at NLL to improve grain production, disease and pest management and health benefits of the grain. However, studies have been hindered by a lack of extensive genomic resources for the species. Results A NLL BAC library was constructed consisting of 111,360 clones with an average insert size of 99.7 Kbp from cv Tanjil. The library has approximately 12 × genome coverage. Both ends of 9600 randomly selected BAC clones were sequenced to generate 13985 BAC end-sequences (BESs), covering approximately 1% of the NLL genome. These BESs permitted a preliminary characterisation of the NLL genome such as organisation and composition, with the BESs having approximately 39% G:C content, 16.6% repetitive DNA and 5.4% putative gene-encoding regions. From the BESs 9966 simple sequence repeat (SSR) motifs were identified and some of these are shown to be potential markers. Conclusions The NLL BAC library and BAC-end sequences are powerful resources for genetic and genomic research on lupin. These resources will provide a robust platform for future high-resolution mapping, map-based cloning, comparative genomics and assembly of whole-genome sequencing data for the species. PMID:22014081

  3. Construction and characterization of a human chromosome 2-specific BAC library

    SciTech Connect

    Wang, M.; Shouse, S.; Manson, J.

    1994-12-01

    We have constructed a human chromosome 2-specific bacterial artificial chromosome (BAC) library using DNA from the somatic cell hybrid GM10826. The average size of the clones is about 63 kb. The coverage and distribution of the library were estimated by screening with known polymorphic genetic markers and fluorescence in situ hybridization (FISH). Twenty-one markers tested positive when DNA pools prepared from approximately one-sixth of the library were screened with 33 known markers. This is consistent with the theoretical calculation of 63% coverage at one genomic equivalent. This suggested that the coverage of the library is approximately 5-6X. FISH analysis with 54 BACs revealed single site hybridization to chromosome 2, and the clones were distributed randomly on the chromosome. We have also performed direct sequencing of the BAC insert ends to generate sequence-tagged sites suitable for mapping and chromosome walking. This is the first reported human chromosome 2-specific BAC library and should provide a resource for physical mapping and disease searching for this chromosome. 30 refs., 5 figs.

  4. Infectious delivery of alphaherpesvirus bacterial artificial chromosomes.

    PubMed

    Tobler, Kurt; Fraefel, Cornel

    2015-01-01

    Bacterial artificial chromosomes (BACs) can accommodate and stably propagate the genomes of large DNA viruses in E. coli. As DNA virus genomes are often per se infectious upon transfection into mammalian cells, their cloning in BACs and easy modification by homologous recombination in bacteria has become an important strategy to investigate the functions of individual virus genes. This chapter describes a strategy to clone the genomes of viruses of the Alphaherpesvirinae subfamily within the family of the Herpesviridae, which is a group of large DNA viruses that can establish both lytic and latent infections in most animal species including humans. The cloning strategy includes the following steps: (1) Construction of a transfer plasmid that contains the BAC backbone with selection and screening markers, and targeting sequences which support homologous recombination between the transfer plasmid and the alphaherpesvirus genome. (2) Introduction of the transfer plasmid sequences into the alphaherpesvirus genome via homologous recombination in mammalian cells. (3) Isolation of recombinant virus genomes containing the BAC backbone sequences from infected mammalian cells and electroporation into E. coli. (4) Preparation of infectious BAC DNA from bacterial cultures and transfection into mammalian cells. (5) Isolation and characterization of progeny virus. PMID:25239748

  5. Anhidrotic ectodermal dysplasia gene region cloned in yeast artificial chromosomes

    SciTech Connect

    Kere, J. |; Grzeschik, K.H.; Limon, J.; Gremaud, M.; Schlessinger, D.; De La Chapelle, A.

    1993-05-01

    Anhidrotic ectodermal dysplasia (EDA), an X-chromosomal recessive disorder, is expressed in a few females with chromosomal translocations involving bands Xq12-q13. Using available DNA markers from the region and somatic cell hybrids the authors mapped the X-chromosomal breakpoints in two such translocations. The breakpoints were further mapped within a yeast artificial chromosome contig constructed by chromosome walking techniques. Genomic DNA markers that map between the two translocation breakpoints were recovered representing putative portions of the EDA gene. 32 refs., 3 figs., 1 tab.

  6. [Cashmere goat bacterial artificial chromosome recombination and cell transfection system].

    PubMed

    Huang, Tian; Cao, Zhongyang; Yang, Yaohui; Cao, Gengsheng

    2016-03-01

    The Cashmere goat is mainly used to produce cashmere, which is very popular for its delicate fiber, luscious softness and natural excellent warm property. Keratin associated protein (KAP) and bone morphogenetic protein (BMP) of the Cashmere goat play an important role in the proliferation and development of cashmere fiber follicle cells. Bacterial artificial chromosome containing kap6.3, kap8.1 and bmp4 genes were used to increase the production and quality of Cashmere. First, we constructed bacterial artificial chromosomes by homology recombination. Then Tol2 transposon was inserted into bacterial artificial chromosomes that were then transfected into Cashmere goat fibroblasts by Amaxa Nucleofector technology according to the manufacture's instructions. We successfully constructed the BAC-Tol2 vectors containing target genes. Each vector contained egfp report gene with UBC promoter, Neomycin resistant gene for cell screening and two loxp elements for resistance removing after transfected into cells. The bacterial artificial chromosome-Tol2 vectors showed a high efficiency of transfection that can reach 1% to 6% with a highest efficiency of 10%. We also obtained Cashmere goat fibroblasts integrated exogenous genes (kap6.3, kap8.1 and bmp4) preparing for the clone of Cashmere goat in the future. Our research demonstrates that the insertion of Tol2 transposons into bacterial artificial chromosomes improves the transfection efficiency and accuracy of bacterial artificial chromosome error-free recombination. PMID:27349114

  7. Construction of DNA libraries from flow sorted human chromosomes

    SciTech Connect

    Deaven, L.L.; McCormick, M.K.; Grady, D.L.

    1994-09-01

    We have constructed a series of DNA libraries from flow-sorted chromosomes. Small insert, complete digest libraries cloned into the EcoRI insertion site of Charon 21A are available from the American Type Culture Collection, Rockville, MD. Partial digest libraries cloned into cosmid (sCos1) or phage (Charon 40) vectors have been constructed for chromosomes 4, 5, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 20, X and Y. Purity estimates by in situ analysis of sorted chromosomes, flow karyotype analysis, and plaque or colony hybridization indicate that most of these libraries are 90-95% pure. Additional cosmid library constructions, 5-10X arrays of libraries into microtiter plates, and high density membrane arrays of libraries are in progress. Recently, we have completed YAC libraries for chromosomes 5, 9, 16, and 21. These libraries are made from complete DNA digests using the rare cutters Clal, SacII, EagI, or NotI/NheI. The average insert size is {similar_to}200 kb, and chimera frequencies are low (1-10%). Libraries have also been constructed using M13 or bluescript vectors (chromosomes 5, 7, 17) to generate STS markers for the selection of chromosome-specific inserts from total genomic AC libraries. Because of the advantages of insert size and stability associated with BAC and PAC cloning systems, we are currently attempting to adapt pBAC108L and pCYPAC1 vectors for use with flow-sorted chromosomal DNA.

  8. Multicolor chromosome banding (MCB) with YAC/BAC-based probes and region-specific microdissection DNA libraries

    SciTech Connect

    Liehr, T.; Weise, A.; Heller, A.; Starke, H.; Mrasek, K.; Kuechler, A.; Weier, H.-U.G.; Claussen, U.

    2003-06-23

    Multicolor chromosome banding (MCB) allows the delineation of chromosomal regions with a resolution of a few mega base pairs, i.e., slightly below the size of most visible chromosome bands. Based on the hybridization of over lapping region-specific probe libraries, chromosomal subregions are hybridized with probes that fluoresce in distinct wave length intervals, so they can be assigned predefined pseudo-colors during the digital imaging and visualization process. The present study demonstrates how MCB patterns can be produced by region-specific micro dissection derived (mcd) libraries as well as collections of yeast or bacterial artificial chromosomes (YACs and BACs, respectively). We compared the efficiency of an mcd library based approach with the hybridization of collections of locus-specific probes (LSP) for fluorescent banding of three rather differently sized human chromosomes, i.e., chromosomes 2, 13, and 22. The LSP sets were comprised of 107 probes specific for chromosome 2, 82 probes for chromosome 13, and 31 probes for chromosome 22. The results demonstrated a more homogeneous coverage of chromosomes and thus, more desirable banding patterns using the microdissection library-based MCB. This may be related to the observation that chromosomes are difficult to cover completely with YAC and/or BAC clones as single-color fluorescence in situ hybridization (FISH) experiments showed. Mcd libraries, on the other hand, provide high complexity probes that work well as region specific paints, but do not readily allow positioning of break points on genetic or physical maps as required for the positional cloning of genes. Thus, combinations of mcd libraries and locus-specific large insert DNA probes appear to be the most efficient tools for high-resolution cytogenetic analyses.

  9. Human chromosome-specific DNA libraries: construction and availability

    SciTech Connect

    Van Dilla, M.A.; Deaven, L.L.; Albright, K.L.; Allen, N.A.; Aubuchon, M.R.; Bartholdi, M.F.; Brown, N.C.; Campbell, E.W.; Carrano, A.V.; Clark, L.M.; Cram, L.S.

    1986-06-01

    The goal of the National Laboratory Gene Library Project at the Los Alamos and Lawrence Livermore National Laboratories is the production of chromosome-specific human gene libraries and their distribution to the scientific community for studies of the molecular biology of genes and chromosomes, and for the study and diagnosis of genetic disease. The specific aim of Phase I of the project is the production of complete digest (4 kb average insert size) libraries from each of the 24 human chromosomal types purified by flow sorting. The bacteriophage vector is Charon 21A, which has both Eco R1 and Hind III insertion sites accommodating human DNA fragments up to 9.1 kb in size. Each laboratory has undertaken production of a complete set of chromosome-specific libraries, Los Alamos with Eco R1 and Livermore with Hind III; most of this task has now been accomplished. Close to 1200 library aliquots have been sent to about 300 laboratories world-wide through February 1986, at which time repository and distribution functions were transferred to the American Type Culture Collection, Rockville, MD. Following Phase I, libraries will be constructed with large inserts in a more advanced, recently developed bacteriophage vector (about 20 kb inserts) or in a cosmid vector (about 40 kb inserts), and with characteristics better suited to basic studies of gene structure and function.

  10. Isolation, characterization, and regional mapping of microclones from a human chromosome 21 microdissection library

    SciTech Connect

    Yu, J.; Hartz, J.; Yisheng Xu; Gemmill, R.M.; Patterson, D.; Kao, Faten ); Gemmill, R.M.; Patterson, D.; Kao, Fa-Ten ); Korenberg, J.R. )

    1992-08-01

    Thirty-four unique-sequence microclones were isolated from a previously described microdissection library of human chromosome 21 and were regionally mapped using a cell hybrid mapping panel which consists of six cell hybrids and divides chromosome 21 into eight regions. The mapping results showed that the microclones were unevenly distributed along chromosome 21, with the majority of microclones located in the distal half portion of the long arm, between 21q21.3 and 21qter. The number of unique-sequence clones began to decrease significantly from 21q21.2 to centromere and extending to the short arm. This finding is consistent with those reported in other chromosome 21 libraries. Thus, it may be inferred that the proximal portion of the long arm of chromosome 21 contains higher proportions of repetitive sequences, rather than unique sequences of genes. The microclones were also characterized for insert size and were used to identify the corresponding genomic fragments generated by HindIII. In addition, the authors demonstrated that the microclones with short inserts can be efficiently used to identify YAC (yeast artificial chromosome) clones with large inserts, for increased genomic coverage for high-resolution physical mapping. They also used 200 unique-sequence microclones to screen a human liver cDNA library and identified two cDNA clones which were regionally assigned to the 21q21.3-q22.1 region. Thus, generation of unique-sequence microclones from chromosome 21 appears to be useful to isolate and regionally map many cDNA clones, among which will be candidate genes for important diseases on chromosome 21, including Down syndrome, Alzheimer disease, amyotrophic lateral sclerosis, and one form of epilepsy.

  11. Isolation of mini- and microsatellite loci from chromosome 19 library

    SciTech Connect

    Prosnyak, M.I.; Belajeva, O.V.; Polukarova, L.G.

    1994-09-01

    Mini- and microsatellite sequences are abundant in the human genome and are very useful as genetic markers. We report the isolation of a panel of clones containing marker sequences from chromosome 19. We screened 10,000 clones from the chromosome 19 cosmid library for the presence of di-(CA)n, tri-(TCC)n, (CAC)n microsatellites and M13-like minisatellite sequences. For this we have used synthetic oligonucleotides and polynucleotides, including micro- (CA, TCC, CAC) and minisatellite (M13 core) sequences. Preliminary results indicated that the chromosome 19 cosmid library contained both human and hamster clones. In order to identify human sequences from this library we have developed the technique of colony and blot hybridization with Alu-PCR, L1-PCR and B1-PCR probes. Dozens of clones have been selected, some of which were analyzed by conventional Southern blot analysis and non-radioactive in situ hybridization of chromosomes. Highly informative markers derived from these clones will be used for physical and genetic mapping of chromosome 19.

  12. Integrative bacterial artificial chromosomes for DNA integration into the Bacillus subtilis chromosome.

    PubMed

    Juhas, Mario; Ajioka, James W

    2016-06-01

    Bacillus subtilis is a well-characterized model bacterium frequently used for a number of biotechnology and synthetic biology applications. Novel strategies combining the advantages of B. subtilis with the DNA assembly and editing tools of Escherichia coli are crucial for B. subtilis engineering efforts. We combined Gibson Assembly and λ red recombineering in E. coli with RecA-mediated homologous recombination in B. subtilis for bacterial artificial chromosome-mediated DNA integration into the well-characterized amyE target locus of the B. subtilis chromosome. The engineered integrative bacterial artificial chromosome iBAC(cav) can accept any DNA fragment for integration into B. subtilis chromosome and allows rapid selection of transformants by B. subtilis-specific antibiotic resistance and the yellow fluorescent protein (mVenus) expression. We used the developed iBAC(cav)-mediated system to integrate 10kb DNA fragment from E. coli K12 MG1655 into B. subtilis chromosome. iBAC(cav)-mediated chromosomal integration approach will facilitate rational design of synthetic biology applications in B. subtilis. PMID:27033694

  13. Drought-tolerant rice germplasm developed from an Oryza officinalis transformation-competent artificial chromosome clone.

    PubMed

    Liu, R; Zhang, H H; Chen, Z X; Shahid, M Q; Fu, X L; Liu, X D

    2015-01-01

    Oryza officinalis has proven to be a natural gene reservoir for the improvement of domesticated rice as it carries many desirable traits; however, the transfer of elite genes to cultivated rice by conventional hybridization has been a challenge for rice breeders. In this study, the conserved sequence of plant stress-related NAC transcription factors was selected as a probe to screen the O. officinalis genomic transformation-competent artificial chromosome library by Southern blot; 11 positive transformation-competent artificial chromosome clones were subsequently detected. By Agrobacterium-mediated transformation, an indica rice variety, Huajingxian 74 (HJX74), was transformed with a TAC clone harboring a NAC gene-positive genomic fragment from O. officinalis. Molecular analysis revealed that the O. officinalis genomic fragment was integrated into the genome of HJX74. The transgenic lines exhibited high tolerance to drought stress. Our results demonstrate that the introduction of stress-related transformation-competent artificial chromosome clones, coupled with a transgenic validation approach, is an effective method of transferring agronomically important genes from O. officinalis to cultivated rice. PMID:26535682

  14. A Yeast Artificial Chromosome Clone Map of the Drosophila Genome

    PubMed Central

    Cai, H.; Kiefel, P.; Yee, J.; Duncan, I.

    1994-01-01

    We describe the mapping of 979 randomly selected large yeast artificial chromosome (YAC) clones of Drosophila DNA by in situ hybridization to polytene chromosomes. Eight hundred and fifty-five of the clones are euchromatic and have primary hybridization sites in the banded portions of the polytene chromosomes, whereas 124 are heterochromatic and label the chromocenter. The average euchromatic clone contains about 211 kb and, at its primary site, labels eight or nine contiguous polytene bands. Thus, the extent as well as chromosomal position of each clone has been determined. By direct band counts, we estimate our clones provide about 76% coverage of the euchromatin of the major autosomes, and 63% coverage of the X. When previously reported YAC mapping data are combined with ours, euchromatic coverage is extended to about 90% for the autosomes and 82% for the X. The distribution of gap sizes in our map and the coverage achieved are in good agreement with expectations based on the assumption of random coverage, indicating that euchromatic clones are essentially randomly distributed. However, certain gaps in coverage, including the entire fourth chromosome euchromatin, may be significant. Heterochromatic sequences are underrepresented among the YAC clones by two to three fold. This may result, at least in part, from underrepresentation of heterochromatic sequences in adult DNA (the source of most of the clones analyzed), or from clone instability. PMID:8013915

  15. HACking the centromere chromatin code: insights from human artificial chromosomes.

    PubMed

    Bergmann, Jan H; Martins, Nuno M C; Larionov, Vladimir; Masumoto, Hiroshi; Earnshaw, William C

    2012-07-01

    The centromere is a specialized chromosomal region that serves as the assembly site of the kinetochore. At the centromere, CENP-A nucleosomes form part of a chromatin landscape termed centrochromatin. This chromatin environment conveys epigenetic marks regulating kinetochore formation. Recent work sheds light on the intricate relationship between centrochromatin state, the CENP-A assembly pathway and the maintenance of centromere function. Here, we review the emerging picture of how chromatin affects mammalian kinetochore formation. We place particular emphasis on data obtained from Human Artificial Chromosome (HAC) biology and the targeted engineering of centrochromatin using synthetic HACs. We discuss implications of these findings, which indicate that a delicate balance of histone modifications and chromatin state dictates both de novo centromere formation and the maintenance of centromere identity in dividing cell populations. PMID:22825423

  16. A human chromosome 11 NotI end clone library

    SciTech Connect

    Sanford, J.; Bupwan Kim; Higgins, M.; Nowak, N.J.; Shows, T.B. ); Deaven, L.L. ); Jones, C. )

    1993-03-01

    A NotI end clone library has been constructed from a human-hamster hybrid cell line containing only human chromosome 11. Fifty-one NotI clones were chosen to characterize the library. The majority of NotI clones hybridize to small 15- to 200-kb fragments and have proven to be valuable for chromosome 11 physical mapping by detecting fragments not previously recognized by random probes. These NotI end clones have been used to isolate corresponding NotI linking cosmids which were then used to identify adjacent NotI fragments on pulsed-field gels. The clones were mapped using fluorescence in situ hybridization and a somatic cell hybrid panel. Although these clones were localized over the entirety of chromosome 11, a nonrandom distribution was observed. Northern blot analysis indicated that 57% (17/30) of the NotI clones examined detected poly(A)[sup +] transcripts in HeLa cell RNA. 34 refs., 6 figs., 1 tab.

  17. Chromosome region-specific libraries for human genome analysis. Progress report, September 1, 1991--August 31, 1992

    SciTech Connect

    Kao, Fa-Ten

    1992-08-01

    During the grant period progress has been made in the successful demonstration of regional mapping of microclones derived from microdissection libraries; successful demonstration of the feasibility of converting microclones with short inserts into yeast artificial chromosome clones with very large inserts for high resolution physical mapping of the dissected region; Successful demonstration of the usefulness of region-specific microclones to isolate region-specific cDNA clones as candidate genes to facilitate search for the crucial genes underlying genetic diseases assigned to the dissected region; and the successful construction of four region-specific microdissection libraries for human chromosome 2, including 2q35-q37, 2q33-q35, 2p23-p25 and 2p2l-p23. The 2q35-q37 library has been characterized in detail. The characterization of the other three libraries is in progress. These region-specific microdissection libraries and the unique sequence microclones derived from the libraries will be valuable resources for investigators engaged in high resolution physical mapping and isolation of disease-related genes residing in these chromosomal regions.

  18. A MOLECULAR CYTOGENETICS MAP OF SORGHUM CHROMOSOME 1: FLUORESCENCE IN SITU HYBRIDIZATION ANALYSIS WITH MAPPED BACTERIAL ARTIFICIAL CHROMOSOMES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We used structural genomic resources for sorghum to target and develop multiple molecular cytogenetic probes that would provide extensive coverage for a specific chromosome of sorghum. Bacterial artificial chromosome clones containing molecular markers mapped across sorghum linkage group A were labe...

  19. Generation of bacterial artificial chromosome (BAC) transgenic mice.

    PubMed

    Beil, Jane; Buch, Thorsten

    2014-01-01

    Transgenic mice are among the most helpful tools to study the role of genes in physiological conditions. In this protocol, we describe the generation of bacterial artificial chromosome (BACs) constructs, which are used to express a gene of interest under a particular promoter. BACs as driver of transgenes have the advantage that a characterization of transcriptional control elements is unnecessary and the construct's size usually reduces position effects from random integration. In the following, we firstly explain in detail the amplification of the BAC, the generation of the targeting construct as well as the recombination by ET-cloning, and the analysis of the recombined clones by Southern blot analysis. Finally, we also describe the preparation of the BACs for oocyte injection. In total, the construction of such BAC transgenes needs around 6-8 weeks. PMID:25064102

  20. Chromosome region-specific libraries for human genome analysis

    SciTech Connect

    Kao, Fa-Ten.

    1991-01-01

    We have made important progress since the beginning of the current grant year. We have further developed the microdissection and PCR- assisted microcloning techniques using the linker-adaptor method. We have critically evaluated the microdissection libraries constructed by this microtechnology and proved that they are of high quality. We further demonstrated that these microdissection clones are useful in identifying corresponding YAC clones for a thousand-fold expansion of the genomic coverage and for contig construction. We are also improving the technique of cloning the dissected fragments in test tube by the TDT method. We are applying both of these PCR cloning technique to human chromosomes 2 and 5 to construct region-specific libraries for physical mapping purposes of LLNL and LANL. Finally, we are exploring efficient procedures to use unique sequence microclones to isolate cDNA clones from defined chromosomal regions as valuable resources for identifying expressed gene sequences in the human genome. We believe that we are making important progress under the auspices of this DOE human genome program grant and we will continue to make significant contributions in the coming year. 4 refs., 4 figs.

  1. Duplication-deficiency of the short arm of chromosome 8 following artificial insemination.

    PubMed

    Weleber, R G; Verma, R S; Kimberling, W J; Fieger, H G; lubs, H A

    1976-12-01

    A chromosomally abnormal child with psychomotor retardation and multiple anomalies, including agenesis of the corpus callosum and cleft palate, was born following artificial insemination by donor. Chromosomal and conventional markers were used to ascertain paternity. Various banding techniques were employed to identify the origin of the extra chromosomal material as most likely a duplication-deficiency of the short arm of chromosome No. 8. PMID:1087853

  2. Genetic manipulation of poxviruses using bacterial artificial chromosome recombineering.

    PubMed

    Cottingham, Matthew G

    2012-01-01

    Traditional methods for genetic manipulation of poxviruses rely on low-frequency natural recombination in virus-infected cells. Although these powerful systems represent the technical foundation of current knowledge and applications of poxviruses, they require long (≥ 500 bp) flanking sequences for homologous recombination, an efficient viral selection method, and burdensome, time-consuming plaque purification. The beginning of the twenty-first century has seen the application of bacterial artificial chromosome (BAC) technology to poxviruses as an alternative method for their genetic manipulation, following the invention of a long-sought-after method for deriving a BAC clone of vaccinia virus (VAC-BAC) by Arban Domi and Bernard Moss. The key advantages of the BAC system are the ease and versatility of performing genetic manipulation using bacteriophage λ Red recombination (recombineering), which requires only ∼50 bp homology arms that can be easily created by PCR, and which allows seamless mutations lacking any marker gene without having to perform transient-dominant selection. On the other hand, there are disadvantages, including the significant setup time, the risk of contamination of the cloned genome with bacterial insertion sequences, and the nontrivial issue of removal of the BAC cassette from derived viruses. These must be carefully weighed to decide whether the use of BACs will be advantageous for a particular application, making pox-BAC systems likely to complement, rather than supplant, traditional methods in most laboratories. PMID:22688760

  3. Selection of chromosomal DNA libraries using a multiplex CRISPR system

    PubMed Central

    Ryan, Owen W; Skerker, Jeffrey M; Maurer, Matthew J; Li, Xin; Tsai, Jordan C; Poddar, Snigdha; Lee, Michael E; DeLoache, Will; Dueber, John E; Arkin, Adam P; Cate, Jamie HD

    2014-01-01

    The directed evolution of biomolecules to improve or change their activity is central to many engineering and synthetic biology efforts. However, selecting improved variants from gene libraries in living cells requires plasmid expression systems that suffer from variable copy number effects, or the use of complex marker-dependent chromosomal integration strategies. We developed quantitative gene assembly and DNA library insertion into the Saccharomyces cerevisiae genome by optimizing an efficient single-step and marker-free genome editing system using CRISPR-Cas9. With this Multiplex CRISPR (CRISPRm) system, we selected an improved cellobiose utilization pathway in diploid yeast in a single round of mutagenesis and selection, which increased cellobiose fermentation rates by over 10-fold. Mutations recovered in the best cellodextrin transporters reveal synergy between substrate binding and transporter dynamics, and demonstrate the power of CRISPRm to accelerate selection experiments and discoveries of the molecular determinants that enhance biomolecule function. DOI: http://dx.doi.org/10.7554/eLife.03703.001 PMID:25139909

  4. Construction of a yeast artificial chromosome contig encompassing the chromosome 14 Alzheimer`s disease locus

    SciTech Connect

    Sharma, V.; Bonnycastle, L.; Poorkai, P.

    1994-09-01

    We have constructed a yeast artificial chromosome (YAC) contig of chromosome 14q24.3 which encompasses the chromosome 14 Alzheimer`s disease locus (AD3). Determined by linkage analysis of early-onset Alzheimer`s disease kindreds, this interval is bounded by the genetic markers D14S61-D14S63 and spans approximately 15 centimorgans. The contig consists of 29 markers and 74 YACs of which 57 are defined by one or more sequence tagged sites (STSs). The STS markers comprise 5 genes, 16 short tandem repeat polymorphisms and 8 cDNA clones. An additional number of genes, expressed sequence tags and cDNA fragments have been identified and localized to the contig by hybridization and sequence analysis of anonymous clones isolated by cDNA direct selection techniques. A minimal contig of about 15 YACs averaging 0.5-1.5 megabase in length will span this interval and is, at first approximation, in rough agreement with the genetic map. For two regions of the contig, our coverage has relied on L1/THE fingerprint and Alu-PCR hybridization data of YACs provided by CEPH/Genethon. We are currently developing sequence tagged sites from these to confirm the overlaps revealed by the fingerprint data. Among the genes which map to the contig are transforming growth factor beta 3, c-fos, and heat shock protein 2A (HSPA2). C-fos is not a candidate gene for AD3 based on the sequence analysis of affected and unaffected individuals. HSPA2 maps to the proximal edge of the contig and Calmodulin 1, a candidate gene from 4q24.3, maps outside of the region. The YAC contig is a framework physical map from which cosmid or P1 clone contigs can be constructed. As more genes and cDNAs are mapped, a highly resolved transcription map will emerge, a necessary step towards positionally cloning the AD3 gene.

  5. Human Artificial Chromosomes for Gene Delivery and the Development of Animal Models

    PubMed Central

    Kazuki, Yasuhiro; Oshimura, Mitsuo

    2011-01-01

    Random integration of conventional gene delivery vectors such as viruses, plasmids, P1 phage-derived artificial chromosomes, bacterial artificial chromosomes and yeast artificial chromosomes can be associated with transgene silencing. Furthermore, integrated viral sequences can activate oncogenes adjacent to the insertion site resulting in cancer. Various human artificial chromosomes (HACs) exhibit several potential characteristics desired for an ideal gene delivery vector, including stable episomal maintenance and the capacity to carry large genomic loci with their regulatory elements, thus allowing the physiological regulation of the introduced gene in a manner similar to that of native chromosomes. HACs have been generated mainly using either a “top-down approach” (engineered chromosomes), or a “bottom-up approach” (de novo artificial chromosomes). The recent emergence of stem cell–based tissue engineering has opened up new avenues for gene and cell therapies. This review describes the lessons learned and prospects identified mainly from studies in the construction of HACs and HAC-mediated gene expression systems in cultured cells, as well as in animals. PMID:21750534

  6. Construction of a chromosome specific library of human MARs and mapping of matrix attachment regions on human chromosome 19.

    PubMed Central

    Nikolaev, L G; Tsevegiyn, T; Akopov, S B; Ashworth, L K; Sverdlov, E D

    1996-01-01

    Using a novel procedure a representative human chromosome 19-specific library was constructed of short sequences, which bind preferentially to the nuclear matrix (matrix attachment regions, or MARs). Judging by 20 clones sequenced so far, the library contains > 50% of human inserts, about 90% of which are matrix-binding by the in vitro test. Computer analysis of sequences of eight human MARs did not reveal any significant homologies with the EMBL Nucleotide Data Base entries as well as between MARs themselves. Eight MARs were assigned to individual positions on the chromosome 19 physical map. The library constructed can serve as a good source of MAR sequences for comparative analysis and classification and for further chromosome mapping of MARs as well. PMID:8614638

  7. Isolation of yeast artificial chromosomes free of endogenous yeast chromosomes: construction of alternate hosts with defined karyotypic alterations.

    PubMed Central

    Hamer, L; Johnston, M; Green, E D

    1995-01-01

    An intrinsic feature of yeast artificial chromosomes (YACs) is that the cloned DNA is generally in the same size range (i.e., approximately 200-2000 kb) as the endogenous yeast chromosomes. As a result, the isolation of YAC DNA, which typically involves separation by pulsed-field gel electrophoresis, is frequently confounded by the presence of a comigrating or closely migrating endogenous yeast chromosome(s). We have developed a strategy that reliably allows the isolation of any YAC free of endogenous yeast chromosomes. Using recombination-mediated chromosome fragmentation, a set of Saccharomyces cerevisiae host strains was systematically constructed. Each strain contains defined alterations in its electrophoretic karyotype, which provide a large-size interval devoid of endogenous chromosomes (i.e., a karyotypic "window"). All of the constructed strains contain the kar1-delta 15 mutation, thereby allowing the efficient transfer of a YAC from its original host into an appropriately selected window strain using the kar1-transfer procedure. This approach provides a robust and efficient means to obtain relatively pure YAC DNA regardless of YAC size. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8524833

  8. Construction and availability of human chromosome-specific gene libraries

    SciTech Connect

    Fuscoe, J.C.; Van Dilla, M.A.; Deaven, L.L.

    1985-06-14

    This report briefly describes Phase I of the project, the production of complete digest fibraries. Each laboratory is currently in the process of sorting individual human chromosomes from normal human fibroblasts or human X hamster hybrids. The goal of 4 x 10/sup 6/ chromosomes for cloning purposes has been achieved. Each laboratory is also in the process of cloning the chromosomal DNA, after complete digestion with a 6-cutter, into the bacteriophage vector Charon 21A. 3 refs.

  9. The Arabidopsis TAC Position Viewer: a high-resolution map of transformation-competent artificial chromosome (TAC) clones aligned with the Arabidopsis thaliana Columbia-0 genome.

    PubMed

    Hirose, Yoshitsugu; Suda, Kunihiro; Liu, Yao-Guang; Sato, Shusei; Nakamura, Yukino; Yokoyama, Koji; Yamamoto, Naoki; Hanano, Shigeru; Takita, Eiji; Sakurai, Nozomu; Suzuki, Hideyuki; Nakamura, Yasukazu; Kaneko, Takakazu; Yano, Kentaro; Tabata, Satoshi; Shibata, Daisuke

    2015-09-01

    We present a high-resolution map of genomic transformation-competent artificial chromosome (TAC) clones extending over all Arabidopsis thaliana (Arabidopsis) chromosomes. The Arabidopsis genomic TAC clones have been valuable genetic tools. Previously, we constructed an Arabidopsis genomic TAC library consisting of more than 10,000 TAC clones harboring large genomic DNA fragments extending over the whole Arabidopsis genome. Here, we determined 13,577 end sequences from 6987 Arabidopsis TAC clones and mapped 5937 TAC clones to precise locations, covering approximately 90% of the Arabidopsis chromosomes. We present the large-scale data set of TAC clones with high-resolution mapping information as a Java application tool, the Arabidopsis TAC Position Viewer, which provides ready-to-go transformable genomic DNA clones corresponding to certain loci on Arabidopsis chromosomes. The TAC clone resources will accelerate genomic DNA cloning, positional walking, complementation of mutants and DNA transformation for heterologous gene expression. PMID:26227242

  10. Rapid construction of a Bacterial Artificial Chromosomal (BAC) expression vector using designer DNA fragments.

    PubMed

    Chen, Chao; Zhao, Xinqing; Jin, Yingyu; Zhao, Zongbao Kent; Suh, Joo-Won

    2014-11-01

    Bacterial artificial chromosomal (BAC) vectors are increasingly being used in cloning large DNA fragments containing complex biosynthetic pathways to facilitate heterologous production of microbial metabolites for drug development. To express inserted genes using Streptomyces species as the production hosts, an integration expression cassette is required to be inserted into the BAC vector, which includes genetic elements encoding a phage-specific attachment site, an integrase, an origin of transfer, a selection marker and a promoter. Due to the large sizes of DNA inserted into the BAC vectors, it is normally inefficient and time-consuming to assemble these fragments by routine PCR amplifications and restriction-ligations. Here we present a rapid method to insert fragments to construct BAC-based expression vectors. A DNA fragment of about 130 bp was designed, which contains upstream and downstream homologous sequences of both BAC vector and pIB139 plasmid carrying the whole integration expression cassette. In-Fusion cloning was performed using the designer DNA fragment to modify pIB139, followed by λ-RED-mediated recombination to obtain the BAC-based expression vector. We demonstrated the effectiveness of this method by rapid construction of a BAC-based expression vector with an insert of about 120 kb that contains the entire gene cluster for biosynthesis of immunosuppressant FK506. The empty BAC-based expression vector constructed in this study can be conveniently used for construction of BAC libraries using either microbial pure culture or environmental DNA, and the selected BAC clones can be directly used for heterologous expression. Alternatively, if a BAC library has already been constructed using a commercial BAC vector, the selected BAC vectors can be manipulated using the method described here to get the BAC-based expression vectors with desired gene clusters for heterologous expression. The rapid construction of a BAC-based expression vector facilitates

  11. A 6. 5-Mb yeast artificial chromosome contig incorporating 33 DNA markers on the human X chromosome at Xq22

    SciTech Connect

    Vetrie, D.; Kendall, E.; Coffey, A.; Hassock, S.; Collins, J.; Todd, C.; Bobrow, M.; Bentley, D.R. ); Lehrach, H. ); Harris, A. )

    1994-01-01

    The Xq22 region of the human X chromosome contains genes for a number of inherited disorders. Sixty-nine yeast artificial chromosome clones have been isolated and assembled into a 6.5-Mb contig that contains 33 DNA markers localized to this region. This contig extends distally from DXS366 to beyond DXS87 and includes the genes involved in X-linked agammaglobulinemia (btk), Fabry disease (GLA), and Pelizaeus-Merzbacher disease (PLP). The order of markers in this contig is consistent with the known genetic and physical mapping information of Xq22. This cloned material provides a source from which to isolate other genes located in this part of the X chromosome. 45 refs., 2 figs., 2 tabs.

  12. A molecular cytogenetic map of sorghum chromosome 1. Fluorescence in situ hybridization analysis with mapped bacterial artificial chromosomes.

    PubMed Central

    Islam-Faridi, M N; Childs, K L; Klein, P E; Hodnett, G; Menz, M A; Klein, R R; Rooney, W L; Mullet, J E; Stelly, D M; Price, H J

    2002-01-01

    We used structural genomic resources for Sorghum bicolor (L.) Moench to target and develop multiple molecular cytogenetic probes that would provide extensive coverage for a specific chromosome of sorghum. Bacterial artificial chromosome (BAC) clones containing molecular markers mapped across sorghum linkage group A were labeled as probes for fluorescence in situ hybridization (FISH). Signals from single-, dual-, and multiprobe BAC-FISH to spreads of mitotic chromosomes and pachytene bivalents were associated with the largest sorghum chromosome, which bears the nucleolus organizing region (NOR). The order of individual BAC-FISH loci along the chromosome was fully concordant to that of marker loci along the linkage map. In addition, the order of several tightly linked molecular markers was clarified by FISH analysis. The FISH results indicate that markers from the linkage map positions 0.0-81.8 cM reside in the short arm of chromosome 1 whereas markers from 81.8-242.9 cM are located in the long arm of chromosome 1. The centromere and NOR were located in a large heterochromatic region that spans approximately 60% of chromosome 1. In contrast, this region represents only 0.7% of the total genetic map distance of this chromosome. Variation in recombination frequency among euchromatic chromosomal regions also was apparent. The integrated data underscore the value of cytological data, because minor errors and uncertainties in linkage maps can involve huge physical regions. The successful development of multiprobe FISH cocktails suggests that it is feasible to develop chromosome-specific "paints" from genomic resources rather than flow sorting or microdissection and that when applied to pachytene chromatin, such cocktails provide an especially powerful framework for mapping. Such a molecular cytogenetic infrastructure would be inherently cross-linked with other genomic tools and thereby establish a cytogenomics system with extensive utility in development and application

  13. BACTERIAL ARTIFICIAL CHROMOSOME-BASED PHYSICAL MAP OF GIBBERELLA ZEAE (FUSARIUM GRAMINEARUM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fusarium graminearum is the primary causal pathogen of Fusarium head blight of wheat and barley, a major disease problem in the wheat and barley growing regions of the world. To accelerate genomic analysis of F. graminearum, we developed a bacterial artificial chromosome (BAC)-based physical map and...

  14. Complete Genome Sequence of a Human Cytomegalovirus Strain AD169 Bacterial Artificial Chromosome Clone

    PubMed Central

    Ostermann, Eleonore; Spohn, Michael; Indenbirken, Daniela

    2016-01-01

    The complete sequence of the human cytomegalovirus strain AD169 (variant ATCC) cloned as a bacterial artificial chromosome (AD169-BAC, also known as HB15 or pHB15) was determined. The viral genome has a length of 230,290 bp and shows 52 nucleotide differences compared to a previously sequenced AD169varATCC clone. PMID:27034483

  15. Identification and cloning in yeast artificial chromosomes of a region of elevated loss of heterozygosity on chromosome 1p31.1 in human breast cancer

    SciTech Connect

    Hoggard, N.; Hey, Y.; Brintnell, B.; James, L.

    1995-11-20

    We have mapped a region of high loss of heterozygosity in breast cancer to a 2-cM interval between the loci D1S430 and D1S465 on chromosome 1p31.1. This region shows allelic imbalance in around 60% of breast tumors. As part of a strategy to clone the target gene(s) within this interval, we have generated a yeast artificial chromosome contig spanning over 7 Mb. YACs from the CEPH and Zeneca (formerly ICI) libraries have been obtained by screening with PCR-based STSs from the region for both previously identified loci and newly isolated STSs. The YACs have been assembled into a contig by a combination of approaches, including analysis of their STS content, generation of new STSs from the ends of key YACs, and long-range restriction mapping. These YAC clones provide the basis for complete characterization of the region of high loss in breast cancer and for the ultimate identification of the target gene(s). 84 refs., 3 figs., 3 tabs.

  16. Comparative study of artificial chromosome centromeres in human and murine cells

    PubMed Central

    Moralli, Daniela; Jefferson, Andrew; Valeria Volpi, Emanuela; Larin Monaco, Zoia

    2013-01-01

    Human artificial chromosomes (HAC) are a valuable tool in the analysis of complex chromatin structures such as the human centromere because of their small size and relative simplicity compared with normal human chromosomes. This report includes a comprehensive study of the centromere and chromatin composition of HAC, expressing human genes, generated in human cells and transferred to murine cells. The analysis involved chromatin immuno-precipitation and immuno-FISH on metaphase chromosomes and chromatin fibres. In both the cell types, the HAC consisted of alphoid and non-alphoid DNA and were mainly euchromatic in composition, although a pericentromeric heterochromatic region was present on all the HAC. Fibre-FISH and chromatin immuno-precipitation data indicated that the position of the centromere differed between HAC in human cells and in murine cells. Our work highlights the importance and utilisation of HAC for understanding the epigenetic aspects of chromosome biology. PMID:23403904

  17. Gene recovery microdissection (GRM) a process for producing chromosome region-specific libraries of expressed genes

    SciTech Connect

    Christian, A T; Coleman, M A; Tucker, J D

    2001-02-08

    Gene Recovery Microdissection (GRM) is a unique and cost-effective process for producing chromosome region-specific libraries of expressed genes. It accelerates the pace, reduces the cost, and extends the capabilities of functional genomic research, the means by which scientists will put to life-saving, life-enhancing use their knowledge of any plant or animal genome.

  18. Development of inter-specific chromosomes segment substitution libraries (CSSL) in rice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six libraries of inter-specific Chromosome Segment Substitution Lines (CSSLs) of rice are being developed as pre-breeding materials and genetic stocks. Three accessions of O. rufipogon were selected as donors, based on phylogenetic, geographical and morphological divergence, and crossed with two rec...

  19. Six rice chromosome segment substitution lines libraries with O. rufipogon introgressions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Chromosome segment substitution lines (CSSLs) are a powerful tool for identifying naturally occurring, favorable alleles in unadapted germplasm. Six CSSL libraries in rice (Oryza sativa) were developed from crosses between three different accessions ('Khao Pa', W1944, IRGC105567) of the rice progeni...

  20. Construction, arraying, and high-density screening of large insert libraries of human chromosomes X and 21: Their potential use as reference libraries

    SciTech Connect

    Nizetic, D.; Zehetner, G.; Monaco, A.P.; Gellen, L.; Lehrach, H. ); Young, B.D. )

    1991-04-15

    The authors have constructed cosmid libraries from flow-sorted human chromosomes X and 21, each of which contains {gt}30 genome equivalents, and have developed systems allowing permanent storage of primary clones, easy screening of libraries in high-density filter formats, and the simultaneous generation of fingerprinting and mapping data on the same set of cosmid clones. Clones are picked into microtiter plate wells and stored at {minus}70C. A semiautomatic robot system allows the generation of filter replicas containing up to 10,000 clones per membrane. Sets of membranes containing 15-20 chromosome equivalents of both chromosomes will be used for the construction of ordered clone libraries by hybridization fingerprinting protocols. The authors describe the construction of the libraries and demonstrate the use of high-density screening filters in oligonucleotide probe hybridizations and the isolation of cosmids by hybridization with probes from the X chromosome.

  1. Construction of a general human chromosome jumping library, with application to cystic fibrosis

    SciTech Connect

    Collins, F.S.; Drumm, M.L.; Cole, J.L.; Lockwood, W.K.; Woude, G.F.V.; Iannuzzi, M.C.

    1987-02-27

    In many genetic disorders, the responsible gene and its protein product are unknown. The technique known as reverse genetics, in which chromosomal map positions and genetically linked DNA markers are used to identify and clone such genes, is complicated by the fact that the molecular distances from the closest DNA markers to the gene itself are often too large to traverse by standard cloning techniques. To address this situation, a general human chromosome jumping library was constructed that allows the cloning of DNA sequences approximately 100 kilobases away from any starting point in genomic DNA. As an illustration of its usefulness, this library was searched for a jumping clone, starting at the met oncogene, which is a marker tightly linked to the cystic fibrosis gene that is located on human chromosome 7. Mapping of the new genomic fragment by pulsed field gel electrophoresis confirmed that it resides on chromosome 7 within 240 kilobases downstream of the met gene. The use of chromosome jumping should be applicable to any genetic locus for which a closely linked DNA marker is available.

  2. A FISH approach for mapping the human genome using Bacterial Artificial Chromosomes (BACs)

    SciTech Connect

    Hubert, R.S.; Chen, X.N.; Mitchell, S.

    1994-09-01

    As the Human Genome Project progresses, large insert cloning vectors such as BACs, P1, and P1 Artificial Chromosomes (PACs) will be required to complement the YAC mapping efforts. The value of the BAC vector for physical mapping lies in the stability of the inserts, the lack of chimerism, the length of inserts (up to 300 kb), the ability to obtain large amounts of pure clone DNA and the ease of BAC manipulation. These features helped us design two approaches for generating physical mapping reagents for human genetic studies. The first approach is a whole genome strategy in which randomly selected BACs are mapped, using FISH, to specific chromosomal bands. To date, 700 BACs have been mapped to single chromosome bands at a resolution of 2-5 Mb in addition to BACs mapped to 14 different centromeres. These BACs represent more than 90 Mb of the genome and include >70% of all human chromosome bands at the 350-band level. These data revealed that >97% of the BACs were non-chimeric and have a genomic distribution covering most gaps in the existing YAC map with excellent coverage of gene-rich regions. In the second approach, we used YACs to identify BACs on chromosome 21. A 1.5 Mb contig between D21S339 and D21S220 nears completion within the Down syndrome congenital heart disease (DS-CHD) region. Seventeen BACs ranging in size from 80 kb to 240 kb were ordered using 14 STSs with FISH confirmation. We have also used 40 YACs spanning 21q to identify, on average, >1 BAC/Mb to provide molecular cytogenetic reagents and anchor points for further mapping. The contig generated on chromosome 21 will be helpful in isolating the genes for DS-CHD. The physical mapping reagents generated using the whole genome approach will provide cytogenetic markers and mapped genomic fragments that will facilitate positional cloning efforts and the identification of genes within most chromosomal bands.

  3. Characterization of four human YAC libraries for clone size, chimerism and X chromosome sequence representation.

    PubMed Central

    Nagaraja, R; Kere, J; MacMillan, S; Masisi, M J; Johnson, D; Molini, B J; Halley, G R; Wein, K; Trusgnich, M; Eble, B

    1994-01-01

    Four collections of human X-specific YACs, derived from human cells containing supernumerary X chromosomes or from somatic cell hybrids containing only X human DNA were characterized. In each collection, 80-85% of YAC strains contained a single X YAC. Five thousand YACs from the various libraries were sized, and cocloning was assessed in subsets by the fraction of YAC insert-ends with non-X sequences. Cocloning was substantial, ranging up to 50% for different collections; and in agreement with previous indications, in all libraries the larger the YACs, the higher the level of cocloning. In libraries made from human-hamster hybrid cells, expected numbers of clones were recovered by STS-based screening; but unexpectedly, the two collections from cells with 4 or 5 X chromosomes yielded numbers of YACs corresponding to an apparent content of only about two X equivalents. Thus it is possible that the DNA of inactive X chromosomes is poorly cloned into YACs, speculatively perhaps because of its specialized chromatin structure. Images PMID:8078777

  4. Large-scale cloning of human chromosome 2-specific yeast artificial chromosomes (YACs) using an interspersed repetitive sequences (IRS)-PCR approach

    SciTech Connect

    Liu, J.; Rezonzew, R. |; Stanton, V.P. Jr.

    1995-03-20

    We report here an efficient approach to the establishment of extended YAC contigs on human chromosome 2 by using an interspersed repetitive sequences (IRS)-PCR-based screening strategy for YAC DNA pools. Genomic DNA was extracted from 1152 YAC pools comprised of 55,296 YACs mostly derived from the CEPH Mark I library. Alu-element-mediated PCR was performed for each pool, and amplification products were spotted on hybridization membranes (IRS filters). IRS probes for the screening of the IRS filters were obtained by Alu-element-mediated PCR. Of 708 distinct probes obtained from chromosome 2-specific somatic cell hybrids, 85% were successfully used for library screening. Similarly, 80% of 80 YAC walking probes were successfully used for library screening. Each probe detected an average of 6.6 YACs, which is in good agreement with the 7- to 7.5-fold genome coverage provided by the library. In a preliminary analysis, we have identified 188 YAC groups that are the basis for building contigs for chromosome 2. The coverage of the telomeric half of chromosome 2q was considered to be good since 31 of 34 microsatellites and 22 of 23 expressed sequence tags that were chosen from chromosome region 2q13-q37 were contained in a chromosome 2 YAC sublibrary generated by our experiments. We have identified a minimum of 1610 distinct chromosome 2-specific YACs, which will be a valuable asset for the physical mapping of the second largest human chromosome. 81 refs., 8 figs., 3 tabs.

  5. Engineering Infectious cDNAs of Coronavirus as Bacterial Artificial Chromosomes

    PubMed Central

    Almazán, Fernando; Márquez-Jurado, Silvia; Nogales, Aitor; Enjuanes, Luis

    2016-01-01

    The large size of the coronavirus (CoV) genome (around 30 kb) and the instability in bacteria of plasmids carrying CoV replicase sequences, represent serious restrictions for the development of CoV infectious clones using reverse genetic systems similar to those used for smaller positive sense RNA viruses. To overcome these problems, several approaches have been established in the last thirteen years. Here we describe the engineering of CoV full-length cDNA clones as bacterial artificial chromosomes (BACs), using the Middle East respiratory syndrome CoV (MERS-CoV) as a model. PMID:25720478

  6. Bacterial artificial chromosome transgenesis through pronuclear injection of fertilized mouse oocytes.

    PubMed

    Vintersten, Kristina; Testa, Giuseppe; Naumann, Ronald; Anastassiadis, Konstantinos; Stewart, A Francis

    2008-01-01

    In the mouse, conventional transgenes often produced unpredictable results mainly because they were too small to recapitulate a natural gene context. Bacterial artificial chromosomes (BACs) are large enough to encompass the natural context of most mammalian genes and consequently deliver more reliable recapitulations of their endogenous counterparts. Furthermore, recombineering methods now make it easy to engineer precise changes in a BAC transgene. Consequently, BACs have become the preferred vehicle for mouse transgenesis. Here, we detail methods for BAC transgenesis through pronuclear injection of fertilized oocytes. PMID:18370149

  7. Chromosome region-specific libraries for human genome analysis. Final progress report, 1 March 1991--28 February 1994

    SciTech Connect

    Kao, F.T.

    1994-04-01

    The objectives of this grant proposal include (1) development of a chromosome microdissection and PCR-mediated microcloning technology, (2) application of this microtechnology to the construction of region-specific libraries for human genome analysis. During this grant period, the authors have successfully developed this microtechnology and have applied it to the construction of microdissection libraries for the following chromosome regions: a whole chromosome 21 (21E), 2 region-specific libraries for the long arm of chromosome 2, 2q35-q37 (2Q1) and 2q33-q35 (2Q2), and 4 region-specific libraries for the entire short arm of chromosome 2, 2p23-p25 (2P1), 2p21-p23 (2P2), 2p14-p16 (wP3) and 2p11-p13 (2P4). In addition, 20--40 unique sequence microclones have been isolated and characterized for genomic studies. These region-specific libraries and the single-copy microclones from the library have been used as valuable resources for (1) isolating microsatellite probes in linkage analysis to further refine the disease locus; (2) isolating corresponding clones with large inserts, e.g. YAC, BAC, P1, cosmid and phage, to facilitate construction of contigs for high resolution physical mapping; and (3) isolating region-specific cDNA clones for use as candidate genes. These libraries are being deposited in the American Type Culture Collection (ATCC) for general distribution.

  8. Construction of a DNA library representing 15q11-13 by subtraction of two flow sorted marker chromosome-specific libraries

    SciTech Connect

    Blennow, E.; Werelius, B.; Nordenskjoeld, M.

    1994-09-01

    Constitutional extra {open_quotes}marker chromosomes{close_quotes} are found in {approx}0.5/1000 of newborns. Of these, 50% are inverted duplications of the pericentromeric region of chromosome 15, including two variants; (1) inv dup(15)(pter{yields}q11:q11{yields}pter) and (2) inv dup(15) (pter{yields}q12-13::q12-13{yields}pter). Variant (1) is found in phenotypically normal individuals, whereas variant (2) will produce a typical clinical picture including mental retardation, autism, hyperactivity and discrete dysmorphic features. Fluorescence in situ hybridization (FISH) using single copy probes from the Prader-Willi region confirms these observations as well as chromosome painting using a flow-sorted marker chromosome-specific library from a variant (1) marker, hybridized to the chromosomes of a patient with a variant (2) marker chromosome. Followingly, a flow-sorted biotinylated variant (1) library was subtracted from a non-labeled variant (2) library using magnetic beads and subsequent amplification by degenerate oligonucleotide-primed PCR (DOP-PCR). The successful result was demonstrated by using the amplified material for chromosome painting on chromosome slides from variant (1) and variant (2) patients. We have constructed a library from 15q11-13. This region contains genes producing a specific abnormal phenotype when found in a tri- or tetrasomic state. The region also contains the genes responsible for the Prader-Willi and Angelman syndromes when the paternal/maternal copy is missing, respectively. It is therefore a region where parental imprinting plays an important role. The isolated library may be used to isolate single copy clones which will allow further investigations of this region.

  9. Artificial Chromosomes to Explore and to Exploit Biosynthetic Capabilities of Actinomycetes

    PubMed Central

    Alduina, Rosa; Gallo, Giuseppe

    2012-01-01

    Actinomycetes are an important source of biologically active compounds, like antibiotics, antitumor agents, and immunosuppressors. Genome sequencing is revealing that this class of microorganisms has larger genomes relative to other bacteria and uses a considerable fraction of its coding capacity (5–10%) for the production of mostly cryptic secondary metabolites. To access actinomycetes biosynthetic capabilities or to improve the pharmacokinetic properties and production yields of these chemically complex compounds, genetic manipulation of the producer strains can be performed. Heterologous expression in amenable hosts can be useful to exploit and to explore the genetic potential of actinomycetes and not cultivable but interesting bacteria. Artificial chromosomes that can be stably integrated into the Streptomyces genome were constructed and demonstrated to be effective for transferring entire biosynthetic gene clusters from intractable actinomycetes into more suitable hosts. In this paper, the construction of several shuttle Escherichia coli-Streptomyces artificial chromosomes is discussed together with old and new strategies applied to improve heterologous production of secondary metabolites. PMID:22919271

  10. Preparation of PAC libraries. Final technical report

    SciTech Connect

    Pieter J. de Jong

    1997-12-31

    The goals of this project were to create P1 Artificial Chromosome (PAC) cloning vectors and use these vectors to generate, characterize, and distribute both human and mouse genomic PAC libraries to the scientific community.

  11. Human Xq24-Xq28: approaches to mapping with yeast artificial chromosomes.

    PubMed Central

    Wada, M; Little, R D; Abidi, F; Porta, G; Labella, T; Cooper, T; Della Valle, G; D'Urso, M; Schlessinger, D

    1990-01-01

    One hundred twenty-seven yeast strains with artificial chromosomes containing Xq24-Xqter human DNA were obtained starting from a human/hamster somatic cell hybrid. The clones were characterized with respect to their insert size, stability, and representation of a set of Xq24-Xqter DNA probes. The inserts of the clones add up to 19.3 megabase (Mb) content, or about 0.4 genomic equivalents of that portion of the X chromosome, with a range of 40-650 kb in individual YACs. Eleven clones contained more than one YAC, the additional ones usually having hamster DNA inserts; the individual YACs could be separated by extracting the total DNA from such strains and using it to retransform yeast cells. One of the YACs, containing the probe for the DXS49 locus, was grossly unstable, throwing off smaller versions of an initial 300-kb YAC during subculture; the other YACs appeared to breed true on subculture. Of 52 probes tested, 12 found cognate YACs; the YACs included one with the glucose-6-phosphate dehydrogense gene and another containing four anonymous probe sequences (DX13, St14, cpx67, and cpx6). Xq location of YACs is being verified by in situ hybridization to metaphase chromosomes, and fingerprinting and hybridization methods are being used to detect YACs that overlap. Images Figure 3 Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 PMID:2294758

  12. Preparation and characterization of ordered libraries of transcribable sequences from human chromosome 19 from hybrid human-hamster cells

    SciTech Connect

    Obradovick, D.; Borodin, A.M.; Kopantsev, E.P.

    1994-08-20

    Improvements in the preparation of chromosome-specific libraries of transcribable sequences from the human genome using somatic hybrid cells are described. One of the main advantages of the new method is the enrichment of the starting material with human-specific heterogeneous nuclear RNA (hnRNA) sequences at each of the three steps in library construction. The method was used to prepare a chromosome-specific library from a hybrid cell line. The resulting ranged library was characterized. The primary structures of 80 randomly selected clones were determined, and these were analyzed. Some 95% of the clones were found to be human-specific and to have arisen from hnRNA, and the chromosomal localizations of a number of clones were identified. The advantages and disadvantages of the method are discussed. 34 refs., 3 figs., 2 tabs.

  13. [New method of construction of artificial translational-coupled operons in bacterial chromosome].

    PubMed

    Gulevich, A Iu; Skorokhodova, A Iu; Ermishev, V Iu; Krylov, A A; Minaeva, N I; Polonskaia, Z M; Zimenkov, D V; Biriukova, I V; Mashko, S V

    2009-01-01

    The new method of translational-coupled operons construction in bacterial chromosome has been developed on the basis of recombineering approach. It includes construction in vitro of the artificial operon with efficiently translated proximal cistron followed by its insertion E. coli chromosome, modification of the operon due to Red-driven insertion of the special "Junction" with excisable selective marker in the intercistronic region of the initial operon and excising the marker. The structure of this Junction has been designed and tested in the present investigation. It consists of: 1) E. coli rplC-rplD intercistronic region for placing the TAA-codon of the proximal operon's gene in the SD-sequence (TAAGGAG) of rplD; 2) Cm(R)-gene flanked by lambdaattL/R-sites in such a fashion that after lambdaInt/Xis-driven excision of the marker the residual lambdaattB-site would not contain the termination codons in frame with ATG of rplD; 3) E. coli trpE-trpD intercistronic region for location of ATG of trpD at the position of initiation codon of the distal gene of original operon. The general design of desired construction provides the conversion of the original two-cistronic operon into three-cistronic operon with translational-coupled genes, where the coupling of the artificial ORF (rplD'-lambdaattB-'trpE) with the proximal gene is occurred due to rplC-rplD intercistronic region and the coupling of this ORF with the distal gene--due to trpE-trpD. The experimental implementation of the described strategy was showed by construction of artificial operon P(tac-aroG4-serA5, where expression optimization of the distal serA5 gene was achieved via construction of three-cistronic operon with translational-coupled genes. PMID:19548541

  14. Chromosome

    MedlinePlus

    ... if you are born a boy or a girl (your gender). They are called sex chromosomes: Females have 2 X chromosomes. Males have 1 X and 1 Y chromosome. The mother gives an X chromosome to the ... baby is a girl or a boy. The remaining chromosomes are called ...

  15. Chromosome

    MedlinePlus

    ... genes . It is the building block of the human body. Chromosomes also contain proteins that help DNA exist ... come in pairs. Normally, each cell in the human body has 23 pairs of chromosomes (46 total chromosomes). ...

  16. Construction and characterization of bacterial artificial chromosomes (BACs) containing herpes simplex virus full-length genomes.

    PubMed

    Nagel, Claus-Henning; Pohlmann, Anja; Sodeik, Beate

    2014-01-01

    Bacterial artificial chromosomes (BACs) are suitable vectors not only to maintain the large genomes of herpesviruses in Escherichia coli but also to enable the traceless introduction of any mutation using modern tools of bacterial genetics. To clone a herpes simplex virus genome, a BAC replication origin is first introduced into the viral genome by homologous recombination in eukaryotic host cells. As part of their nuclear replication cycle, genomes of herpesviruses circularize and these replication intermediates are then used to transform bacteria. After cloning, the integrity of the recombinant viral genomes is confirmed by restriction length polymorphism analysis and sequencing. The BACs may then be used to design virus mutants. Upon transfection into eukaryotic cells new herpesvirus strains harboring the desired mutations can be recovered and used for experiments in cultured cells as well as in animal infection models. PMID:24671676

  17. Complementation of the beige mutation in cultured cells by episomally replicating murine yeast artificial chromosomes

    SciTech Connect

    Perou, C.M.; Pryor, R.J.; Kaplan, J.; Justice, M.J.

    1996-06-11

    Chediak-Higashi syndrome in man and the beige mutation of mice are phenotypically similar disorders that have profound effects upon lysosome and melansosome morphology and function. We isolated two murine yeast artificial chromosomes (YACs) that, when introduced into beige mouse fibroblasts, complement the beige mutation. The complementing YACs exist as extrachromosomal elements that are amplified in high concentrations of G418. When YAC-complemented beige cells were fused to human Chediak-Higashi syndrome or Aleutian mink fibroblasts, complementation of the mutant phenotype also occurred. These results localize the beige gene to a 500-kb interval and demonstrate that the same or homologous genes are defective in mice, minks, and humans. 16 refs., 5 figs.

  18. A Plasmid Set for Efficient Bacterial Artificial Chromosome (BAC) Transgenesis in Zebrafish

    PubMed Central

    Fuentes, Fernando; Reynolds, Eric; Lewellis, Stephen W.; Venkiteswaran, Gayatri; Knaut, Holger

    2016-01-01

    Transgenesis of large DNA constructs is essential for gene function analysis. Recently, Tol2 transposase-mediated transgenesis has emerged as a powerful tool to insert bacterial artificial chromosome (BAC) DNA constructs into the genome of zebrafish. For efficient transgenesis, the genomic DNA piece in the BAC construct needs to be flanked by Tol2 transposon sites, and the constructs should contain a transgenesis marker for easy identification of transgenic animals. We report a set of plasmids that contain targeting cassettes that allow the insertion of Tol2 sites and different transgenesis markers into BACs. Using BACs containing these targeting cassettes, we show that transgenesis is as efficient as iTol2, that preselecting for expression of the transgenesis marker increases the transgenesis rate, and that BAC transgenics faithfully recapitulate the endogenous gene expression patterns and allow for the estimation of the endogenous gene expression levels. PMID:26818072

  19. A Plasmid Set for Efficient Bacterial Artificial Chromosome (BAC) Transgenesis in Zebrafish.

    PubMed

    Fuentes, Fernando; Reynolds, Eric; Lewellis, Stephen W; Venkiteswaran, Gayatri; Knaut, Holger

    2016-01-01

    Transgenesis of large DNA constructs is essential for gene function analysis. Recently, Tol2 transposase-mediated transgenesis has emerged as a powerful tool to insert bacterial artificial chromosome (BAC) DNA constructs into the genome of zebrafish. For efficient transgenesis, the genomic DNA piece in the BAC construct needs to be flanked by Tol2 transposon sites, and the constructs should contain a transgenesis marker for easy identification of transgenic animals. We report a set of plasmids that contain targeting cassettes that allow the insertion of Tol2 sites and different transgenesis markers into BACs. Using BACs containing these targeting cassettes, we show that transgenesis is as efficient as iTol2, that preselecting for expression of the transgenesis marker increases the transgenesis rate, and that BAC transgenics faithfully recapitulate the endogenous gene expression patterns and allow for the estimation of the endogenous gene expression levels. PMID:26818072

  20. Engineering the largest RNA virus genome as an infectious bacterial artificial chromosome

    PubMed Central

    Almazán, Fernando; González, José M.; Pénzes, Zoltan; Izeta, Ander; Calvo, Enrique; Plana-Durán, Juan; Enjuanes, Luis

    2000-01-01

    The construction of cDNA clones encoding large-size RNA molecules of biological interest, like coronavirus genomes, which are among the largest mature RNA molecules known to biology, has been hampered by the instability of those cDNAs in bacteria. Herein, we show that the application of two strategies, cloning of the cDNAs into a bacterial artificial chromosome and nuclear expression of RNAs that are typically produced within the cytoplasm, is useful for the engineering of large RNA molecules. A cDNA encoding an infectious coronavirus RNA genome has been cloned as a bacterial artificial chromosome. The rescued coronavirus conserved all of the genetic markers introduced throughout the sequence and showed a standard mRNA pattern and the antigenic characteristics expected for the synthetic virus. The cDNA was transcribed within the nucleus, and the RNA translocated to the cytoplasm. Interestingly, the recovered virus had essentially the same sequence as the original one, and no splicing was observed. The cDNA was derived from an attenuated isolate that replicates exclusively in the respiratory tract of swine. During the engineering of the infectious cDNA, the spike gene of the virus was replaced by the spike gene of an enteric isolate. The synthetic virus replicated abundantly in the enteric tract and was fully virulent, demonstrating that the tropism and virulence of the recovered coronavirus can be modified. This demonstration opens up the possibility of employing this infectious cDNA as a vector for vaccine development in human, porcine, canine, and feline species susceptible to group 1 coronaviruses. PMID:10805807

  1. Cloning of a very virulent plus, 686 strain of Marek’s disease virus as a bacterial artificial chromosome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial artificial chromosome (BAC) vectors were first developed to facilitate propagation and manipulation of large DNA fragments. This technology was later used to clone full-length genomes of large DNA viruses to study viral gene function. Marek’s disease virus (MDV) is a highly oncogenic herpe...

  2. Plant artificial chromosome technology and its potential application in genetic engineering.

    PubMed

    Yu, Weichang; Yau, Yuan-Yeu; Birchler, James A

    2016-05-01

    Genetic engineering with just a few genes has changed agriculture in the last 20 years. The most frequently used transgenes are the herbicide resistance genes for efficient weed control and the Bt toxin genes for insect resistance. The adoption of the first-generation genetically engineered crops has been very successful in improving farming practices, reducing the application of pesticides that are harmful to both human health and the environment, and producing more profit for farmers. However, there is more potential for genetic engineering to be realized by technical advances. The recent development of plant artificial chromosome technology provides a super vector platform, which allows the management of a large number of genes for the next generation of genetic engineering. With the development of other tools such as gene assembly, genome editing, gene targeting and chromosome delivery systems, it should become possible to engineer crops with multiple genes to produce more agricultural products with less input of natural resources to meet future demands. PMID:26369910

  3. [Breeding of robust industrial ethanol-tolerant Saccharomyces cerevisiae strain by artificial zinc finger protein library].

    PubMed

    Ma, Cui; Zhao, Xinqing; Li, Qian; Zhang, Mingming; Kim, Jin Soo; Bai, Fengwu

    2013-05-01

    Breeding of robust industrial Saccharomyces cerevisiae strains with high ethanol tolerance is of great significance for efficient fuel ethanol production. Zinc finger proteins play important roles in gene transcription and translation, and exerting control on the regulation of multiple genes. The sequence and localization of the zinc finger motif can be designed and engineered, and the artificial zinc finger protein can be used to regulate celluar metabolism. Stress tolerance of microbial strains is related to multiple genes. Therefore, it is possible to use artificially-designed zinc finger proteins to breed stress tolerant strains. In this study, a library containing artificial zinc finger protein encoding genes was transformed into the model yeast strain S288c. A recombinant strain named M01 with improved ethanol tolerance was obtained. The plasmid in M01 was isolated, and then transformed into the industrial yeast strain Sc4126. Ethanol tolerance of the recombinant strain of Sc4126 were significantly improved. When high gravity ethanol fermentation using 250 g/L glucose was performed, comparing with the wild-type strain, fermentation time of the recombinant strain was decreased by 24 h and the final ethanol concentration was enhanced by 6.3%. The results of this study demonstrate that artificial zinc finger proteins are able to exert control on stress tolerance of yeast strains, and these results provide basis to construct robust industrial yeast strains for efficient ethanol fermentation. PMID:24010359

  4. Mouse embryonic stem cells with a multi-integrase mouse artificial chromosome for transchromosomic mouse generation.

    PubMed

    Yoshimura, Yuki; Nakamura, Kazuomi; Endo, Takeshi; Kajitani, Naoyo; Kazuki, Kanako; Kazuki, Yasuhiro; Kugoh, Hiroyuki; Oshimura, Mitsuo; Ohbayashi, Tetsuya

    2015-08-01

    The mouse artificial chromosome (MAC) has several advantages as a gene delivery vector, including stable episomal maintenance of the exogenous genetic material and the ability to carry large and/or multiple gene inserts including their regulatory elements. Previously, a MAC containing multi-integration site (MI-MAC) was generated to facilitate transfer of multiple genes into desired cells. To generate transchromosomic (Tc) mice containing a MI-MAC with genes of interest, the desired genes were inserted into MI-MAC in CHO cells, and then the MI-MAC was transferred to mouse embryonic stem (mES) cells via microcell-mediated chromosome transfer (MMCT). However, the efficiency of MMCT from CHO to mES cells is very low (<10(-6)). In this study, we constructed mES cell lines containing a MI-MAC vector to directly insert a gene of interest into the MI-MAC in mES cells via a simple transfection method for Tc mouse generation. The recombination rate of the GFP gene at each attachment site (FRT, PhiC31attP, R4attP, TP901-1attP and Bxb1attP) on MI-MAC was greater than 50% in MI-MAC mES cells. Chimeric mice with high coat colour chimerism were generated from the MI-MAC mES cell lines and germline transmission from the chimera was observed. As an example for the generation of Tc mice with a desired gene by the MI-MAC mES approach, a Tc mouse strain ubiquitously expressing Emerald luciferase was efficiently established. Thus, the findings suggest that this new Tc strategy employing mES cells and a MI-MAC vector is efficient and useful for animal transgenesis. PMID:26055730

  5. Development of canine herpesvirus based antifertility vaccines for foxes using bacterial artificial chromosomes.

    PubMed

    Strive, Tanja; Hardy, Christopher M; French, Nigel; Wright, John D; Nagaraja, Nitin; Reubel, Gerhard H

    2006-02-13

    Using bacterial artificial chromosome (BAC) technology, a canine herpesvirus (CHV)-based recombinant vaccine vector was produced for the development of an antifertility vaccine for foxes. Infectious viruses were recovered following transfection of canid cells with a BAC plasmid carrying the complete CHV genome. In vitro growth characteristics of BAC-derived viruses were similar to that of wildtype (wt)-CHV. Two recombinant antigens, fox zona pellucida protein subunit 3 (fZPC) and enhanced green fluorescent protein (EGFP) as control antigen, were inserted into thymidine kinase (TK) locus of the CHV genome and shown to be efficiently expressed in vitro. Inoculation of foxes with transgenic CHVs induced CHV specific antibodies, but was innocuous and failed to elicit transgene-specific antibody responses. Infectious virus or viral DNA was not detected in mucosal secretions or tissues of vaccinated foxes. The CHV-BAC system proved to be a quick and reliable method to manipulate the CHV genome. It will help to readily apply changes in the vector design in order to improve virus replication in vivo. PMID:16198458

  6. Herpesvirus mutagenesis facilitated by infectious bacterial artificial chromosomes (iBACs).

    PubMed

    Robinson, Karl E; Mahony, Timothy J

    2015-01-01

    A critical factor in the study of herpesviruses, their genes and gene functions is the capacity to derive mutants that harbor deletions, truncations, or insertions within the genetic elements of interest. Once constructed the impact of the introduced mutation on the phenotypic properties of the rescued virus can be determined in either in vitro or in vivo systems. However, the construction of such mutants by traditional virological mutagenesis techniques can be a difficult and laborious undertaking. The maintenance of a viral genome as an infectious bacterial artificial chromosome (iBAC), however, endows the capacity to manipulate the viral genome for mutagenesis studies with relative ease. Here, the construction and characterization of two gene deletion mutants of an alphaherpesvirus maintained as iBAC in combination with an inducible homologous recombination system in Escherichia coli is detailed. The methodology is generally applicable to any iBAC and is demonstrated to be a highly efficient and informative approach for mutant virus construction. PMID:25239746

  7. Construction of an infectious clone of canine herpesvirus genome as a bacterial artificial chromosome.

    PubMed

    Arii, Jun; Hushur, Orkash; Kato, Kentaro; Kawaguchi, Yasushi; Tohya, Yukinobu; Akashi, Hiroomi

    2006-04-01

    Canine herpesvirus (CHV) is an attractive candidate not only for use as a recombinant vaccine to protect dogs from a variety of canine pathogens but also as a viral vector for gene therapy in domestic animals. However, developments in this area have been impeded by the complicated techniques used for eukaryotic homologous recombination. To overcome these problems, we used bacterial artificial chromosomes (BACs) to generate infectious BACs. Our findings may be summarized as follows: (i) the CHV genome (pCHV/BAC), in which a BAC flanked by loxP sites was inserted into the thymidine kinase gene, was maintained in Escherichia coli; (ii) transfection of pCHV/BAC into A-72 cells resulted in the production of infectious virus; (iii) the BAC vector sequence was almost perfectly excisable from the genome of the reconstituted virus CHV/BAC by co-infection with CHV/BAC and a recombinant adenovirus that expressed the Cre recombinase; and (iv) a recombinant virus in which the glycoprotein C gene was deleted was generated by lambda recombination followed by Flp recombination, which resulted in a reduction in viral titer compared with that of the wild-type virus. The infectious clone pCHV/BAC is useful for the modification of the CHV genome using bacterial genetics, and CHV/BAC should have multiple applications in the rapid generation of genetically engineered CHV recombinants and the development of CHV vectors for vaccination and gene therapy in domestic animals. PMID:16515874

  8. Delineating Rearrangements in Single Yeast Artificial Chromosomes by Quantitative DNA Fiber Mapping

    SciTech Connect

    Weier, Heinz-Ulrich G.; Greulich-Bode, Karin M.; Wu, Jenny; Duell, Thomas

    2009-09-18

    Cloning of large chunks of human genomic DNA in recombinant systems such as yeast or bacterial artificial chromosomes has greatly facilitated the construction of physical maps, the positional cloning of disease genes or the preparation of patient-specific DNA probes for diagnostic purposes. For this process to work efficiently, the DNA cloning process and subsequent clone propagation need to maintain stable inserts that are neither deleted nor otherwise rearranged. Some regions of the human genome; however, appear to have a higher propensity than others to rearrange in any host system. Thus, techniques to detect and accurately characterize such rearrangements need to be developed. We developed a technique termed 'Quantitative DNA Fiber Mapping (QDFM)' that allows accurate tagging of sequence elements of interest with near kilobase accuracy and optimized it for delineation of rearrangements in recombinant DNA clones. This paper demonstrates the power of this microscopic approach by investigating YAC rearrangements. In our examples, high-resolution physical maps for regions within the immunoglobulin lambda variant gene cluster were constructed for three different YAC clones carrying deletions of 95 kb and more. Rearrangements within YACs could be demonstrated unambiguously by pairwise mapping of cosmids along YAC DNA molecules. When coverage by YAC clones was not available, distances between cosmid clones were estimated by hybridization of cosmids onto DNA fibers prepared from human genomic DNA. In addition, the QDFM technology provides essential information about clone stability facilitating closure of the maps of the human genome as well as those of model organisms.

  9. Development of a Safeguard System Using an Episomal Mammalian Artificial Chromosome for Gene and Cell Therapy.

    PubMed

    Uno, Narumi; Uno, Katsuhiro; Komoto, Shinya; Suzuki, Teruhiko; Hiratsuka, Masaharu; Osaki, Mitsuhiko; Kazuki, Yasuhiro; Oshimura, Mitsuo

    2015-01-01

    The development of a safeguard system to remove tumorigenic cells would allow safer clinical applications of stem cells for the treatment of patients with an intractable disease including genetic disorders. Such safeguard systems should not disrupt the host genome and should have long-term stability. Here, we attempted to develop a tumor-suppressing mammalian artificial chromosome containing a safeguard system that uses the immune rejection system against allogeneic tissue from the host. For proof-of-concept of the safeguard system, B16F10 mouse melanoma cells expressing the introduced H2-K(d) major histocompatibility complex (MHC class I)-allogenic haplotype were transplanted into recipient C57BL/6J mice expressing MHC H2-K(b). Subcutaneous implantation of B16F10 cells into C57BL/6J mice resulted in high tumorigenicity. The volume of tumors derived from B16F10 cells expressing allogenic MHC H2-K(d) was decreased significantly (P < 0.01). Suppression of MHC H2-K(d)-expressing tumors in C57BL/6J mice was enhanced by immunization with MHC H2-K(d)-expressing splenocytes (P < 0.01). These results suggest that the safeguard system is capable of suppressing tumor formation by the transplanted cells. PMID:26670279

  10. Delivery of bacterial artificial chromosomes into mammalian cells with psoralen-inactivated adenovirus carrier.

    PubMed Central

    Baker, A; Cotten, M

    1997-01-01

    Molecular biology has many applications where the introduction of large (>100 kb) DNA molecules is required. The current methods of large DNA transfection are very inefficient. We reasoned that two limits to improving transfection methods with these large DNA molecules were the difficulty of preparing workable quantities of clean DNA and the lack of rapid assays to determine transfection success. We have used bacterial artificial chromosomes (BACs) based on the Escherichia coli F factor plasmid system, which are simple to manipulate and purify in microgram quantities. Because BAC plasmids are kept at one to two copies per cell, the problems of rearrangement observed with YACs are eliminated. We have generated two series of BAC vectors bearing marker genes for luciferase and green fluorescent protein (GFP). Using these reagents, we have developed methods of delivering BACs of up to 170 kb into mammalian cells with transfection efficiency comparable to 5-10 kb DNA. Psoralen-inactivated adenovirus is used as the carrier, thus eliminating the problems associated with viral gene expression. The delivered DNA is linked to the carrier virus with a condensing polycation. Further improvements in gene delivery were obtained by replacing polylysine with low molecular weight polyethylenimine (PEI) as the DNA condensing agent. PMID:9115362

  11. Integration-Free iPS Cells Engineered Using Human Artificial Chromosome Vectors

    PubMed Central

    Hiratsuka, Masaharu; Uno, Narumi; Ueda, Kana; Kurosaki, Hajime; Imaoka, Natsuko; Kazuki, Kanako; Ueno, Etsuya; Akakura, Yutaro; Katoh, Motonobu; Osaki, Mitsuhiko; Kazuki, Yasuhiro; Nakagawa, Masato; Yamanaka, Shinya; Oshimura, Mitsuo

    2011-01-01

    Human artificial chromosomes (HACs) have unique characteristics as gene-delivery vectors, including episomal transmission and transfer of multiple, large transgenes. Here, we demonstrate the advantages of HAC vectors for reprogramming mouse embryonic fibroblasts (MEFs) into induced pluripotent stem (iPS) cells. Two HAC vectors (iHAC1 and iHAC2) were constructed. Both carried four reprogramming factors, and iHAC2 also encoded a p53-knockdown cassette. iHAC1 partially reprogrammed MEFs, and iHAC2 efficiently reprogrammed MEFs. Global gene expression patterns showed that the iHACs, unlike other vectors, generated relatively uniform iPS cells. Under non-selecting conditions, we established iHAC-free iPS cells by isolating cells that spontaneously lost iHAC2. Analyses of pluripotent markers, teratomas and chimeras confirmed that these iHAC-free iPS cells were pluripotent. Moreover, iHAC-free iPS cells with a re-introduced HAC encoding Herpes Simplex virus thymidine kinase were eliminated by ganciclovir treatment, indicating that the HAC safeguard system functioned in iPS cells. Thus, the HAC vector could generate uniform, integration-free iPS cells with a built-in safeguard system. PMID:21998730

  12. Yeast artificial chromosome cloning in the glycerol kinase and adrenal hypoplasia congenita region of Xp21

    SciTech Connect

    Worley, K.C.; Ellison, K.A.; Zhang, Y.H.; Wang, D.F.; Mason, J.; Roth, E.J.; Adams, V.; Fogt, D.D.; Zhu, X.M.; Towbin, J.A.

    1993-05-01

    The adrenal hypoplasia congenita (AHC) and glycerol kinase (GK) loci are telomeric to the Duchenne muscular dystrophy locus in Xp21. The authors developed a pair of yeast artificial chromosome (YAC) contigs spanning at least 1.2 Mb and encompassing the region from the telomeric end of the Duchenne muscular dystrophy (DMD) locus to beyond YHX39 (DXS727), including the genes for AHC and GK. The centromeric contig consists of 13 YACs reaching more than 600 kb from DMD through GK. The telomeric contig group consists of 8 YACs containing more than 600 kb including the markers YHX39 (DXS727) and QST-59 (DXS319). Patient deletion breakpoints in the region of the two YAC contigs define at least eight intervals, and seven deletion breakpoints are contained within these contigs. In addition to the probes developed from YAC ends, they have mapped eight Alu-PCR probes amplified from a radiation-reduced somatic cell hybrid, two anonymous DNA probes, and one Alu-PCR product amplified from a cosmid end, for a total of 26 new markers within this region of 2 Mb or less. One YAC in the centromeric contig contains an insert encompassing the minimum interval for GK deficiency defined by patient deletion breakpoints, and this clone includes all or part of the GK gene. 33 refs., 3 figs., 5 tabs.

  13. Multiplex sequencing of bacterial artificial chromosomes for assembling complex plant genomes.

    PubMed

    Beier, Sebastian; Himmelbach, Axel; Schmutzer, Thomas; Felder, Marius; Taudien, Stefan; Mayer, Klaus F X; Platzer, Matthias; Stein, Nils; Scholz, Uwe; Mascher, Martin

    2016-07-01

    Hierarchical shotgun sequencing remains the method of choice for assembling high-quality reference sequences of complex plant genomes. The efficient exploitation of current high-throughput technologies and powerful computational facilities for large-insert clone sequencing necessitates the sequencing and assembly of a large number of clones in parallel. We developed a multiplexed pipeline for shotgun sequencing and assembling individual bacterial artificial chromosomes (BACs) using the Illumina sequencing platform. We illustrate our approach by sequencing 668 barley BACs (Hordeum vulgare L.) in a single Illumina HiSeq 2000 lane. Using a newly designed parallelized computational pipeline, we obtained sequence assemblies of individual BACs that consist, on average, of eight sequence scaffolds and represent >98% of the genomic inserts. Our BAC assemblies are clearly superior to a whole-genome shotgun assembly regarding contiguity, completeness and the representation of the gene space. Our methods may be employed to rapidly obtain high-quality assemblies of a large number of clones to assemble map-based reference sequences of plant and animal species with complex genomes by sequencing along a minimum tiling path. PMID:26801048

  14. Use of Bacterial Artificial Chromosomes in Baculovirus Research and Recombinant Protein Expression: Current Trends and Future Perspectives

    PubMed Central

    Roy, Polly; Noad, Rob

    2012-01-01

    The baculovirus expression system is one of the most successful and widely used eukaryotic protein expression methods. This short review will summarise the role of bacterial artificial chromosomes (BACS) as an enabling technology for the modification of the virus genome. For many years baculovirus genomes have been maintained in E. coli as bacterial artificial chromosomes, and foreign genes have been inserted using a transposition-based system. However, with recent advances in molecular biology techniques, particularly targeting reverse engineering of the baculovirus genome by recombineering, new frontiers in protein expression are being addressed. In particular, BACs have facilitated the propagation of disabled virus genomes that allow high throughput protein expression. Furthermore, improvement in the selection of recombinant viral genomes inserted into BACS has enabled the expression of multiprotein complexes by iterative recombineering of the baculovirus genome. PMID:23762754

  15. The selection and use of sorghum (Sorghum propinquum) bacterial artificial chromosomes as cytogenetic FISH probes for maize (Zea mays L.).

    PubMed

    Figueroa, Debbie M; Davis, James D; Strobel, Cornelia; Conejo, Maria S; Beckham, Katherine D; Ring, Brian C; Bass, Hank W

    2011-01-01

    The integration of genetic and physical maps of maize is progressing rapidly, but the cytogenetic maps lag behind, with the exception of the pachytene fluorescence in situ hybridization (FISH) maps of maize chromosome 9. We sought to produce integrated FISH maps of other maize chromosomes using Core Bin Marker loci. Because these 1 Kb restriction fragment length polymorphism (RFLP) probes are below the FISH detection limit, we used BACs from sorghum, a small-genome relative of maize, as surrogate clones for FISH mapping. We sequenced 151 maize RFLP probes and compared in silico BAC selection methods to that of library filter hybridization and found the latter to be the best. BAC library screening, clone verification, and single-clone selection criteria are presented along with an example of transgenomic BAC FISH mapping. This strategy has been used to facilitate the integration of RFLP and FISH maps in other large-genome species. PMID:21234422

  16. Stable maintenance of de novo assembled human artificial chromosomes in embryonic stem cells and their differentiated progeny in mice

    PubMed Central

    Liskovykh, Mikhail; Ponomartsev, Sergey; Popova, Elena; Bader, Michael; Kouprina, Natalay; Larionov, Vladimir; Alenina, Natalia; Tomilin, Alexey

    2015-01-01

    De novo assembled alphoidtetO-type human artificial chromosomes (HACs) represent a novel promising generation of high capacity episomal vectors. Their function and persistence, and any adverse effects, in various cell types in live animals, have not, however, been explored. In this study we transferred the alphoidtetO-HAC into mouse ES cells and assessed whether the presence of this extra chromosome affects their pluripotent properties. AlphoidtetO-HAC-bearing ES cells were indistinguishable from their wild-type counterparts: they retained self-renewal potential and full capacity for multilineage differentiation during mouse development, whereas the HAC itself was mitotically and transcriptionally stable during this process. Our data provide the first example of fully synthetic DNA behaving like a normal chromosome in cells of living animals. It also opens a new perspective into functional genetic studies in laboratory animals as well as stem cell-based regenerative medicine. PMID:25695642

  17. Production of a yeast artificial chromosome for stable expression of a synthetic xylose isomerase-xylulokinase polyprotein in a fuel ethanol yeast strain

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Commercialization of fuel ethanol production from lignocellulosic biomass has focused on engineering the glucose-fermenting industrial yeast Saccharomyces cerevisiae to utilize pentose sugars. A yeast artificial chromosome (YAC) was engineered to contain a polyprotein gene construct expressing xylos...

  18. Construction and analysis of an hn-cDNA library derived from the p-arm of pig chromosome 12.

    PubMed

    Anderson Dear, D V; Miller, J R

    1996-09-01

    Our aim is to find unidentified genes on specific pig chromosomes or chromosome fragments. Our approach has involved the construction of a heterogeneous nuclear complementary (hn-c) DNA library of the p-arm of pig Chromosome (Chr) 12, the only pig chromosome present in the pig x hamster hybrid cell line 8990. Total RNA was extracted from the cells and first-strand synthesis of hn-cDNA carried out with random and oligo dT primers. Pig hn-cDNA was isolated by amplification of first-strand synthesized hn-cDNA with primers specific for Short Interspersed Repeat Elements (SINEs) via the polymerase chain reaction (PCR). Hn-cDNAs were size selected and cloned in E. coli XL-1 blue cells with PCR-Script as the vector. The library consisted of 6000 clones. Clone inserts were amplified by PCR with vector-specific primers, and randomly picked inserts greater than 600 bp were sequenced. Homology searches were carried out with the FASTA search program on the GenEmbl database. Thirty clones were sequenced, and of these three showed strong homologies to GenEmbl sequences: (1) to sheep, mouse, human, and rat mammary gland factor (MGF); (2) to MLN-50, a gene that is amplified in human familial breast cancer and is present on human Chr 17; the latter is homologous to pig chromosome 12; (3) to a family of unassigned overlapping human ESTs. Of the other sequenced clones, seven were over 80% homologous with pig SINE sequences; three were over 75% homologous to human LINE sequences; six displayed open reading frames over a mean distance equivalent to 50 amino acids, although these showed no significant similarities with sequences in the databases. Using this approach, we have been able to identify several new genes on the p-arm of pig Chr 12. This is the first report of gene isolation from a library derived from a pig chromosome fragment. PMID:8703117

  19. Genetic Stability of Bacterial Artificial Chromosome-Derived Human Cytomegalovirus during Culture In Vitro

    PubMed Central

    Murrell, Isa; Wilkie, Gavin S.; Davison, Andrew J.; Statkute, Evelina; Fielding, Ceri A.; Tomasec, Peter; Wilkinson, Gavin W. G.

    2016-01-01

    ABSTRACT Clinical human cytomegalovirus (HCMV) strains invariably mutate when propagated in vitro. Mutations in gene RL13 are selected in all cell types, whereas in fibroblasts mutants in the UL128 locus (UL128L; genes UL128, UL130, and UL131A) are also selected. In addition, sporadic mutations are selected elsewhere in the genome in all cell types. We sought to investigate conditions under which HCMV can be propagated without incurring genetic defects. Bacterial artificial chromosomes (BACs) provide a stable, genetically defined source of viral genome. Viruses were generated from BACs containing the genomes of strains TR, TB40, FIX, and Merlin, as well as from Merlin-BAC recombinants containing variant nucleotides in UL128L from TB40-BAC4 or FIX-BAC. Propagation of viruses derived from TR-BAC, TB40-BAC4, and FIX-BAC in either fibroblast or epithelial cells was associated with the generation of defects around the prokaryotic vector, which is retained in the unique short (US) region of viruses. This was not observed for Merlin-BAC, from which the vector is excised in derived viruses; however, propagation in epithelial cells was consistently associated with mutations in the unique long b′ (UL/b′) region, all impacting on gene UL141. Viruses derived from Merlin-BAC in fibroblasts had mutations in UL128L, but mutations occurred less frequently with recombinants containing UL128L nucleotides from TB40-BAC4 or FIX-BAC. Viruses derived from a Merlin-BAC derivative in which RL13 and UL128L were either mutated or repressed were remarkably stable in fibroblasts. Thus, HCMV containing a wild-type gene complement can be generated in vitro by deriving virus from a self-excising BAC in fibroblasts and repressing RL13 and UL128L. IMPORTANCE Researchers should aim to study viruses that accurately represent the causative agents of disease. This is problematic for HCMV because clinical strains mutate rapidly when propagated in vitro, becoming less cell associated, altered in

  20. Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses

    PubMed Central

    Yun, Sang-Im; Song, Byung-Hak; Kim, Jin-Kyoung; Lee, Young-Min

    2015-01-01

    Reverse genetics, an approach to rescue infectious virus entirely from a cloned cDNA, has revolutionized the field of positive-strand RNA viruses, whose genomes have the same polarity as cellular mRNA. The cDNA-based reverse genetics system is a seminal method that enables direct manipulation of the viral genomic RNA, thereby generating recombinant viruses for molecular and genetic studies of both viral RNA elements and gene products in viral replication and pathogenesis. It also provides a valuable platform that allows the development of genetically defined vaccines and viral vectors for the delivery of foreign genes. For many positive-strand RNA viruses such as Japanese encephalitis virus (JEV), however, the cloned cDNAs are unstable, posing a major obstacle to the construction and propagation of the functional cDNA. Here, the present report describes the strategic considerations in creating and amplifying a genetically stable full-length infectious JEV cDNA as a bacterial artificial chromosome (BAC) using the following general experimental procedures: viral RNA isolation, cDNA synthesis, cDNA subcloning and modification, assembly of a full-length cDNA, cDNA linearization, in vitro RNA synthesis, and virus recovery. This protocol provides a general methodology applicable to cloning full-length cDNA for a range of positive-strand RNA viruses, particularly those with a genome of >10 kb in length, into a BAC vector, from which infectious RNAs can be transcribed in vitro with a bacteriophage RNA polymerase. PMID:26780115

  1. Bacterial Artificial Chromosomes: A Functional Genomics Tool for the Study of Positive-strand RNA Viruses.

    PubMed

    Yun, Sang-Im; Song, Byung-Hak; Kim, Jin-Kyoung; Lee, Young-Min

    2015-01-01

    Reverse genetics, an approach to rescue infectious virus entirely from a cloned cDNA, has revolutionized the field of positive-strand RNA viruses, whose genomes have the same polarity as cellular mRNA. The cDNA-based reverse genetics system is a seminal method that enables direct manipulation of the viral genomic RNA, thereby generating recombinant viruses for molecular and genetic studies of both viral RNA elements and gene products in viral replication and pathogenesis. It also provides a valuable platform that allows the development of genetically defined vaccines and viral vectors for the delivery of foreign genes. For many positive-strand RNA viruses such as Japanese encephalitis virus (JEV), however, the cloned cDNAs are unstable, posing a major obstacle to the construction and propagation of the functional cDNA. Here, the present report describes the strategic considerations in creating and amplifying a genetically stable full-length infectious JEV cDNA as a bacterial artificial chromosome (BAC) using the following general experimental procedures: viral RNA isolation, cDNA synthesis, cDNA subcloning and modification, assembly of a full-length cDNA, cDNA linearization, in vitro RNA synthesis, and virus recovery. This protocol provides a general methodology applicable to cloning full-length cDNA for a range of positive-strand RNA viruses, particularly those with a genome of >10 kb in length, into a BAC vector, from which infectious RNAs can be transcribed in vitro with a bacteriophage RNA polymerase. PMID:26780115

  2. Association Between Pachytene Chromosomes and Linkage Groups in Carrot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genome of carrot (Daucus carota L.) consists of ~ 480 Mb/1C organized in 9 chromosome pairs. The importance of carrots in human nutrition is triggering the development of genomic resources, including carrot linkage maps, a bacterial artificial chromosome (BAC) clone library and BAC end sequence...

  3. Narrowing the genetic interval and yeast artificial chromosome map in the branchio-oto-renal region on chromosome 8q

    SciTech Connect

    Kumar, Shrawan; Kimberling, W.J.; Pinnt, J.

    1996-01-01

    Branchio-oto-renal (BOR) syndrome is an autosomal dominant disorder characterized by branchial abnormality, hearing loss, and renal anomalies. Recently, the disease gene has been localized to chromosome 8q. Here, we report genetic studies that further refine the disease gene region to a smaller interval and identify several YACs from the critical region. We studied two large, clinically well-characterized BOR families with a set of 13 polymorphic markers spanning the D8S165-D8S275 interval from the chromosome 8q region. Based on multipoint analysis, the highest likelihood for the location of the BOR gene is between markers D8S543 and D8S530, a distance of about 2 cM. YACs that map in the BOR critical region have been identified and characterized by fluorescence in situ hybridization and pulsed-field gel electrophoresis. A YAC contig, based on the STS content map, that covers a minimum of 4 Mb of human DNA in the critical region of BOR is assembled. This lays the groundwork for the construction of a transcriptional map of this region and the eventual identification of genes involved in BOR syndrome. 40 refs., 4 figs., 1 tab.

  4. Isolation of a yeast artificial chromosome spanning the 8; 21 translocation breakpoint t(8; 21)(q22; q22. 3) in acute myelogenous leukemia

    SciTech Connect

    Jizong Gao; Erickson, P. ); Gardiner, K.; Patterson, D. ); Le Beau, M.M.; Diaz, M.O.; Rowley, J.D. ); Drabkin, H.A. Eleanor Roosevelt Inst. for Cancer Research, Denver, CO )

    1991-06-01

    The 8;21 translocation is one of the most common specific rearrangements in acute myelogenous leukemia. The authors have identified markers (D21S65 and a Not I boundary clone, Not-42, referred to as probe B) flanking the chromosome 21 translocation breakpoint (21q22.3) that demonstrate physical linkage in normal genomic DNA, by using at least three restriction endonucleases (Not I, Sac II, and BssHII), and that are located not more than 250-280 kilobases apart. Pulsed-field gel analysis of DNA from somatic cell hybrids containing the 8;21 translocation chromosomes demonstrates rearrangement of these markers. A 470-kilobase yeast artificial chromosome, YAC-Not-42, has been isolated that contains both probes. Mapping of {lambda} subclones constructed from YAC-Not-42 suggests that >95% of the yeast artificial chromosome DNA is located on the proximal (D21S65) side of the breakpoint. In situ hybridization studies using metaphase chromosomes from five acute myelogenous leukemia patients with the 8;21 translocation confirmed these results and demonstrated the translocation of probe B to the derivative chromosome 8. A chromosome walk of {approx} 39 kilobases from probe B has allowed identification of the breakpoint in DNA from a somatic cell hybrid containing the derivative chromosome 8. Since probe B contains conserved DNA sequences and is in close proximity to the translocation breakpoint, it may represent a portion of the involved gene on chromosome 21.

  5. Use of laser microdissection for the construction of Humulus japonicus Siebold et Zuccarini, 1846 (Cannabaceae) sex chromosome-specific DNA library and cytogenetics analysis

    PubMed Central

    Yakovin, Nickolay A.; Divashuk, Mikhail G.; Razumova, Olga V.; Soloviev, Alexander A.; Karlov, Gennady I.

    2014-01-01

    Abstract Dioecy is relatively rare among plant species, and distinguishable sex chromosomes have been reported in few dioecious species. The multiple sex chromosome system (XX/XY1Y2) of Humulus japonicus Siebold et Zuccarini, 1846 differs from that of other members of the family Cannabaceae, in which the XX/XY chromosome system is present. Sex chromosomes of Humulus japonicus were isolated from meiotic chromosome spreads of males by laser microdissection with the P.A.L.M. MicroLaser system. The chromosomal DNA was directly amplified by degenerate oligonucleotide primed polymerase chain reaction (DOP-PCR). Fast fluorescence in situ hybridization (FAST-FISH) using a labeled, chromosome-specific DOP-PCR product as a probe showed preferential hybridization to sex chromosomes. In addition, the DOP-PCR product was used to construct a short-insert, Humulus japonicus sex chromosomes-specific DNA library. The randomly sequenced clones showed that about 12% of them have significant homology to Humulus lupulus and 88% to Cannabis sativa Linnaeus, 1753 sequences from GenBank database. Forty-four percent of the sequences show homology to plant retroelements. It was concluded that laser microdissection is a useful tool for isolating the DNA of sex chromosomes of Humulus japonicus and for the construction of chromosome-specific DNA libraries for the study of the structure and evolution of sex chromosomes. The results provide the potential for identifying unique or sex chromosome-specific sequence elements in Humulus japonicus and could aid in the identification of sex chromosome-specific repeat and coding regions through chromosome isolation and genome complexity reduction. PMID:25610546

  6. Evaluation of an Hprt-Luciferase Reporter Gene on a Mammalian Artificial Chromosome in Response to Cytotoxicity

    PubMed Central

    Endo, Takeshi; Noda, Natsumi; Kuromi, Yasushi; Kokura, Kenji; Kazuki, Yasuhiro; Oshimura, Mitsuo; Ohbayashi, Tetsuya

    2016-01-01

    Background Hypoxanthine guanine phosphoribosyltransferase (Hprt) is known as a house-keeping gene, and has been used as an internal control for real-time quantitative RT-PCR and various other methods of gene expression analysis. To evaluate the Hprt mRNA levels as a reference standard, we engineered a luciferase reporter driven by a long Hprt promoter and measured its response to cytotoxicity. Methods We constructed a reporter vector that harbored a phiC31 integrase recognition site and a mouse Hprt promoter fused with green-emitting luciferase (SLG) coding sequence. The Hprt-SLG vector was loaded onto a mouse artificial chromosome containing a multi-integrase platform using phiC31 integrase in mouse A9 cells. We established three independent clones. Results The established cell lines had similar levels of expression of the Hprt-SLG reporter gene. Hprt-SLG activity increased proportionately under growth conditions and decreased under cytotoxic conditions after blasticidin or cisplatin administration. Similar increases and decreases in the SLG luminescent were observed under growth and cytotoxic conditions, respectively, to those in the fluorescent obtained using the commercially available reagent, alamarBlue. Conclusion By employing a reliable and stable expression system in a mammalian artificial chromosome, the activity of an Hprt-SLG reporter can reflect cell numbers under cell growth condition and cell viability in the evaluation of cytotoxic conditions. PMID:27493490

  7. In situ hybridization to cytogenetic bands of yeast artificial chromosomes covering 50% of human Xq24-Xq28 DNA

    PubMed Central

    Montanaro, Vittorio; Casamassimi, Amelia; D'Urso, Michele; Yoon, Jae-Young; Freije, Wadiha; Schlessinger, David; Muenke, Maximilian; Nussbaum, Robert L.; Saccone, Salvatore; Maugeri, Silvana; Santoro, Anna Maria; Motta, Salvatore; Della Valle, Giuliano

    1991-01-01

    From the collection described by Abidi et al., 102 yeast artificial chromosomes (YACs) with human DNA inserts more than 300 kb in length were assigned to chromosomal band positions on early metaphase chromosomes by in situ hybridization using the biotin-avidin method. All the YACs hybridized within the Xq24-Xqter region, supporting the origin of the vast majority of the YACs from single human X-chromosomal sites. With assignments precise to ±0.5 bands, YACs were distributed among cytogenetic bands to roughly equal extents. Thus, there is no gross bias in the cloning of DNA from different bands into large YACs. To test band assignments further, hybridizations were carried out blind, and band positions were then compared with (1) probe localizations in cases in which a reported location was present in one of the YACs; (2) cross-hybridization of a labeled YAC with others in the collection; and (3) hybridization to a panel of DNAs from a series of hybrid cells containing Xq DNA truncated at various regions. Of 31 cases in which YACs contained a probe with a previously reported location, 28 in situ assignments were in agreement, and 14 other assignments, including one of the three discordant with probe localization, were confirmed by YAC cross-hybridization studies. Results with a group of nine YACs were further confirmed with a panel of somatic cell hybrid DNAs from that region. Five YACs hybridized both to Xq25 and to a second site (four in Xq27 and one in Xq28), suggestive of some duplication of DNA of the hybrid cell and perhaps in normal X chromosomes. The in situ assignments are thus sufficient to place YACs easily and systematically within bins of about 7–10 Mb and to detect some possible anomalies. Furthermore, on the basis of expectations for random cloning of DNA in YACs, the assigned YACs probably cover more than 50% of the total Xq24-Xq28 region. This provides one way to initiate the assembly of YAC contigs over extended chromosomal regions. Images

  8. A yeast artificial chromosome contig of the critical region for cri-du-chat syndrome

    SciTech Connect

    Goodart, S.A.; Rojas, K.; Overhauser, J.

    1994-11-01

    Cri-du-chat is a chromosomal deletion syndrome characterized by partial deletion of the short arm of chromosome 5. The clinical symptoms include growth and mental retardation, microcephaly, hypertelorism, epicanthal folds, hyptonia, and a high-pitched monochromatic cry that is usually considered diagnostic for the syndrome. Recently, a correlation between clinical features and the extent of the chromosome 5 deletions has identified two regions of the short arm that appear to be critical for the abnormal development manifested in this syndrome. Loss of a small region in 5p15.2 correlates with all of the clinical features of cri-du-chat with the exception of the cat-like cry, which maps to 5p15.3. Here the authors report the construction of a YAC contig that spans the chromosomal region in 5p15.2 that plays a major role in the etiology of the cri-du-chat syndrome. YACs that span the 2-Mb cri-du-chat critical region have been identified and characterized. This YAC contig lays the groundwork for the construction of a transcriptional map of this region and the eventual identification of genes involved in the clinical features associated with the cri-du-chat syndrome. It also provides a new diagnostic tool for cri-du-chat in the shape of a YAC clone that may span the entire critical region. 24 refs., 4 figs., 2 tabs.

  9. Three-region specific microdissection libraries for the long arm of human chromosome 2, regions q33-q35, q31-q32, and q23-q24

    SciTech Connect

    Yu, J.; Tong, S.; Whittier, A.

    1995-09-01

    Three region-specific libraries have been constructed from the long arm of human chromosome 2, including regions 2q33-35 (2Q2 library), 2q31-32 (2Q3) and 2q23-24 (2Q4). Chromosome microdissection and the MboI linker-adaptor microcloning techniques were used in constructing these libraries. The libraries comprised hundreds of thousands of microclones in each library. Approximately half of the microclones in the library contained unique or low-copy number sequence inserts. The insert sizes ranged between 50 and 800 bp, with a mean of 130-190 bp. Southern blot analysis of individual unique sequence microclones showed that 70-94% of the microclones were derived from the dissected region. 31 unique sequence microclones from the 2Q2 library, 31 from 2Q3, and 30 from 2Q4, were analyzed for insert sizes, the hybridizing genomic HindIII fragment sizes, and cross-hybridization to rodent species. These libraries and the short insert microclones derived from the libraries should be useful for high resolution physical mapping, sequence-ready reagents for large scale genomic sequencing, and positional cloning of disease-related genes assigned to these regions, e.g. the recessive familial amyotrophic lateral sclerosis assigned to 2q33-q35, and a type I diabetes susceptibility gene to 2q31-q33. 17 refs., 5 figs., 2 tabs.

  10. Characterization of bacterial artificial chromosome transgenic mice expressing mCherry fluorescent protein substituted for the murine smooth muscle-alpha-actin gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Smooth muscle a actin (SMA) is a cytoskeletal protein expressed by mesenchymal and smooth muscle cell types, including mural cells(vascular smooth muscle cells and pericytes). Using Bacterial Artificial Chromosome (BAC) recombineering technology, we generated transgenic reporter mice that express a ...

  11. Artifically inserting a reticuloendotheliosis virus long terminal repeat into a bacterial artificial chromosome clone of Marek's disease virus (MDV) alters expression of nearby MDV genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The long terminal repeat (LTR) sequence of reticuloendotheliosis virus (REV) was inserted into the very virulent Marek’s disease virus (MDV) Md5 bacterial artificial chromosome clone. The insertion site was nearly identical to the REV LTR that was naturally inserted into the JM/102W strain of MDV fo...

  12. Use of a Human Artificial Chromosome for Delivering Trophic Factors in a Rodent Model of Amyotrophic Lateral Sclerosis

    PubMed Central

    Watanabe, Yasuhiro; Kazuki, Yasuhiro; Kazuki, Kanako; Ebiki, Mitsutaka; Nakanishi, Mami; Nakamura, Kazuomi; Yoshida Yamakawa, Miho; Hosokawa, Hiroyuki; Ohbayashi, Tetsuya; Oshimura, Mitsuo; Nakashima, Kenji

    2015-01-01

    A human artificial chromosome (HAC) is maintained as an episome within a cell and avoids random integration into the host genome. It can transfer multiple and/or large transgenes along with their regulatory elements thereby resembling native chromosomes. Using this HAC system, we established mesenchymal stem cells (MSCs) that simultaneously expressed hepatocyte growth factor, glial cell line-derived neurotrophic factor, and insulin-like growth factor 1, termed HAC-MSCs. This cell line provides an opportunity for stable transplantation and thorough analyses. We then introduced the cells for the treatment of a neurodegenerative disorder, amyotrophic lateral sclerosis. The HAC-MSCs were transplanted via the fourth cerebral ventricle (CV) or intravenous (i.v.) infusion at various ages of recipient mice. Littermate- and sex-matched mice underwent a sham procedure. Compared to the controls, there was an encouraging trend of increased life span via CV transplantation and delayed onset in i.v. infusion 60 days after transplantation. Further, we confirmed a statistically significant increase in life span via CV transplantation at 100 days. This effect was not seen in mice transplanted with MSCs lacking the HAC. We successfully enhanced the trophic potential of the MSCs using the HAC. This strategy could be a promising direction for the treatment of neurodegenerative disorders. PMID:26440597

  13. A bacterial artificial chromosome contig spanning the major domestication locus Q in wheat and identification of a candidate gene.

    PubMed Central

    Faris, Justin D; Fellers, John P; Brooks, Steven A; Gill, Bikram S

    2003-01-01

    The Q locus played a major role in the domestication of wheat because it confers the free-threshing character and influences many other agronomically important traits. We constructed a physical contig spanning the Q locus using a Triticum monococcum BAC library. Three chromosome walking steps were performed by complete sequencing of BACs and identification of low-copy markers through similarity searches of database sequences. The BAC contig spans a physical distance of approximately 300 kb corresponding to a genetic distance of 0.9 cM. The physical map of T. monococcum had perfect colinearity with the genetic map of wheat chromosome arm 5AL. Recombination data in conjunction with analysis of fast neutron deletions confirmed that the contig spanned the Q locus. The Q gene was narrowed to a 100-kb segment, which contains an APETALA2 (AP2)-like gene that cosegregates with Q. AP2 is known to play a major role in controlling floral homeotic gene expression and thus is an excellent candidate for Q. PMID:12750342

  14. Construction and characterization of a NotI linking library from human chromosome region 1q25-qter

    SciTech Connect

    Talmadge, C.B.; Zhen, Dong-Kai; Wang, Ji-Yi

    1995-09-01

    Chromosome 1q25-qter-specific NotI linking clones have been isolated from a NotI linking library that was constructed using DNA from MCH206.1 somatic cell hybrid cells. These cells contain chromosome 1q25-qter translocated to human chromosome Xp22 as the only human genetic material in mouse background. Sixty-eight NotI linking clones have been mapped by a combination of fluorescence in situ hybridization and R-banding to cytogenetic bands on the long arm of chromosome 1. The relative order of 11 NotI clones and their relation to known chromosome 1 markers have also been determined in 1q32 and 1q41, where the genes of Van der Woude and Usher syndrome type IIa have been previously mapped: cen-chr1.14-chr1.79-chr1.56-chr1.11-chr1.95-chr1.58 (chr1.74)-D1S70-chr1.15-chr1.82 (chr1.143)-chr1.62-D1S81-tel. The 1q32- and 1q41-specific NotI linking clones were sequenced in the vicinity of the NotI site. They were analyzed in terms of nucleotide composition, G+C content, frequency of CpG dinucleotides, and protein coding potentials. Most of the 1q32-q41-specific NotI linking clones were derived from CpG islands. Sequences of three NotI linking clones proved to be identical with known genes. Six of the remaining eight had a high potential for coding regions and shared short homologous regions with sequences in the GenBank database. The NotI linking clones and the identified CpG islands will provide valuable resources for constructing a long-range restriction map of chromosome 1q25-q44 and for the eventual isolation of disease genes of Van der Woude syndrome (1q32-q41) and Usher syndrome type IIa (1q41). 29 refs., 2 figs., 3 tabs.

  15. Isolation of cDNAs from the spinal muscular atrophy gene region with yeast artificial chromosomes

    SciTech Connect

    Deng, H.X.; He, X.X.; Hung, W.Y.

    1994-09-01

    Spinal muscular atrophy (SMA) is an autosomal recessive disorder characterized by degeneration of anterior horn cells, leading to progressive paralysis of voluntary muscles. The SMA gene(s) is located at 5q11.2-q13.3, between D5S435 and D5S112. To isolate potential candidate gene(s) responsible for SMA, we used the YACs within the SMA gene region as probes to screen a human brainstem cDNA library. Thirteen cDNA clones were isolated. Their sizes range from 0.7 kb to 5 kb. Seven clones were found to be unique in sequence; the remaining six clones contain repetitive sequences. Five out of these seven unique clones have been used as probes to screen a phage genomic DNA library. Phage genomic clones isolated with individual unique cDNA were used for fluorescence in situ hybridization to identify the origin of cDNAs. These five unique sequences are all located in the 5q13 region, indicating the reliability of our screening method. All the thirteen clones have been partially sequenced (about 300 bp) from each end. No homology has been found with any known EST or known genes. No cross hybridization was detected among the unique clones, suggesting that there may be distinct new genes encoded in this region.

  16. Library+

    ERIC Educational Resources Information Center

    Merrill, Alex

    2011-01-01

    This article discusses possible future directions for academic libraries in the post Web/Library 2.0 world. These possible directions include areas such as data literacy, linked data sets, and opportunities for libraries in support of digital humanities. The author provides a brief sketch of the background information regarding the topics and…

  17. A Chromosome Segment Substitution Library of Weedy Rice for Genetic Dissection of Complex Agronomic and Domestication Traits

    PubMed Central

    Subudhi, Prasanta K.; De Leon, Teresa; Singh, Pradeep K.; Parco, Arnold; Cohn, Marc A.; Sasaki, Takuji

    2015-01-01

    Chromosome segment substitution lines (CSSLs) are a powerful alternative for locating quantitative trait loci (QTL), analyzing gene interactions, and providing starting materials for map-based cloning projects. We report the development and characterization of a CSSL library of a U.S. weedy rice accession ‘PSRR-1’ with genome-wide coverage in an adapted rice cultivar ‘Bengal’ background. The majority of the CSSLs carried a single defined weedy rice segment with an average introgression segment of 2.8 % of the donor genome. QTL mapping results for several agronomic and domestication traits from the CSSL population were compared with those obtained from two recombinant inbred line (RIL) populations involving the same weedy rice accession. There was congruence of major effect QTLs between both types of populations, but new and additional QTLs were detected in the CSSL population. Although, three major effect QTLs for plant height were detected on chromosomes 1, 4, and 8 in the CSSL population, the latter two escaped detection in both RIL populations. Since this was observed for many traits, epistasis may play a major role for the phenotypic variation observed in weedy rice. High levels of shattering and seed dormancy in weedy rice might result from an accumulation of many small effect QTLs. Several CSSLs with desirable agronomic traits (e.g. longer panicles, longer grains, and higher seed weight) identified in this study could be useful for rice breeding. Since weedy rice is a reservoir of genes for many weedy and agronomic attributes, the CSSL library will serve as a valuable resource to discover latent genetic diversity for improving crop productivity and understanding the plant domestication process through cloning and characterization of the underlying genes. PMID:26086245

  18. Construction and characterization of region-specific microdissection libraries and single-copy microclones for short arm of human chromosome 2

    SciTech Connect

    Tu, J.; Kao, F.T. |; Tong, S.; Qi, J.

    1994-07-01

    The short arm of human chromosome 2, comprising approximately 93 million bp, has been divided into four regions to construct region-specific microdissection libraries to facilitate physical mapping and gene cloning. These four regions include 2p23-p25 (designated 2P1), 2p21-p23 (2P2), 2p14-p16 (2P3), and 2p11-p13 (2P4). Together with three previously constructed microdissection libraries of 2P1, 2P2 and 2P4, a fourth library for the region 2P3 has been constructed and characterized to complete all four region-specific libraries for the entire 2p. The 2P3 library is very large, potentially comprising 1,000,000 recombinant microclones with insert sizes ranging between 50 and 800 bp and a mean of 250 bp. Approximately 40% of the microclones contain unique sequences. Of the 77 single-copy microclones analyzed, 66 clones (86%) hybridized to both human and chromosome 2 DNAs, indicating that they were derived from human and are chromosome 2 specific. The hybridizing HindIII genomic fragments for the 66 microclones have also been determined.

  19. Incorporation of a lambda phage recombination system and EGFP detection to simplify mutagenesis of Herpes simplex virus bacterial artificial chromosomes

    PubMed Central

    Schmeisser, Falko; Weir, Jerry P

    2007-01-01

    Background Targeted mutagenesis of the herpesvirus genomes has been facilitated by the use of bacterial artificial chromosome (BAC) technology. Such modified genomes have potential uses in understanding viral pathogenesis, gene identification and characterization, and the development of new viral vectors and vaccines. We have previously described the construction of a herpes simplex virus 2 (HSV-2) BAC and the use of an allele replacement strategy to construct HSV-2 recombinants. While the BAC mutagenesis procedure is a powerful method to generate HSV-2 recombinants, particularly in the absence of selective marker in eukaryotic culture, the mutagenesis procedure is still difficult and cumbersome. Results Here we describe the incorporation of a phage lambda recombination system into an allele replacement vector. This strategy enables any DNA fragment containing the phage attL recombination sites to be efficiently inserted into the attR sites of the allele replacement vector using phage lambda clonase. We also describe how the incorporation of EGFP into the allele replacement vector can facilitate the selection of the desired cross-over recombinant BACs when the allele replacement reaction is a viral gene deletion. Finally, we incorporate the lambda phage recombination sites directly into an HSV-2 BAC vector for direct recombination of gene cassettes using the phage lambda clonase-driven recombination reaction. Conclusion Together, these improvements to the techniques of HSV BAC mutagenesis will facilitate the construction of recombinant herpes simplex viruses and viral vectors. PMID:17501993

  20. Cloning of a very virulent plus, 686 strain of Marek's disease virus as a bacterial artificial chromosome.

    PubMed

    Reddy, Sanjay M; Sun, Aijun; Khan, Owais A; Lee, Lucy F; Lupiani, Blanca

    2013-06-01

    Bacterial artificial chromosome (BAC) vectors were first developed to facilitate propagation and manipulation of large DNA fragments. This technology was later used to clone full-length genomes of large DNA viruses to study viral gene function. Marek's disease virus (MDV) is a highly oncogenic herpesvirus that causes rapid induction of T-cell lymphomas in chickens. Based on the virus's ability to cause disease in vaccinated chickens, MDV strains are classified into pathotypes, with the most virulent strains belonging to the very virulent plus (vv+) pathotype. Here we report the construction of BAC clones of 686 (686-BAC), a vv+ strain of MDV. Transfection of DNA isolated from two independent clones into duck embryo fibroblasts resulted in recovery of infectious virus. Pathogenesis studies showed that the BAC-derived 686 viruses were more virulent than Md5, a vv strain of MDV. With the use of a two-step red-mediated mutagenesis process, both copies of viral interleukin 8 (vIL-8) were deleted from the MDV genome, showing that 686-BACs were amenable to mutagenesis techniques. The generation of BAC clones from a vv+ strain of MDV is a significant step toward understanding molecular basis of MDV pathogenesis. PMID:23901763

  1. The H19 Imprinting Control Region Mediates Preimplantation Imprinted Methylation of Nearby Sequences in Yeast Artificial Chromosome Transgenic Mice

    PubMed Central

    Okamura, Eiichi; Matsuzaki, Hitomi; Sakaguchi, Ryuuta; Takahashi, Takuya; Fukamizu, Akiyoshi

    2013-01-01

    In the mouse Igf2/H19 imprinted locus, differential methylation of the imprinting control region (H19 ICR) is established during spermatogenesis and is maintained in offspring throughout development. Previously, however, we observed that the paternal H19 ICR, when analyzed in yeast artificial chromosome transgenic mice (YAC-TgM), was preferentially methylated only after fertilization. To identify the DNA sequences that confer methylation imprinting, we divided the H19 ICR into two fragments (1.7 and 1.2 kb), ligated them to both ends of a λ DNA fragment into which CTCF binding sites had been inserted, and analyzed this in YAC-TgM. The maternally inherited λ sequence, normally methylated after implantation in the absence of H19 ICR sequences, became hypomethylated, demonstrating protective activity against methylation within the ICR. Meanwhile, the paternally inherited λ sequence was hypermethylated before implantation only when a 1.7-kb fragment was ligated. Consistently, when two subfragments of the H19 ICR were individually investigated for their activities in YAC-TgM, only the 1.7-kb fragment was capable of introducing paternal allele-specific DNA methylation. These results show that postfertilization methylation imprinting is conferred by a paternal allele-specific methylation activity present in a 1.7-kb DNA fragment of the H19 ICR, while maternal allele-specific activities protect the allele from de novo DNA methylation. PMID:23230275

  2. Gata3 Hypomorphic Mutant Mice Rescued with a Yeast Artificial Chromosome Transgene Suffer a Glomerular Mesangial Cell Defect.

    PubMed

    Moriguchi, Takashi; Yu, Lei; Otsuki, Akihito; Ainoya, Keiko; Lim, Kim-Chew; Yamamoto, Masayuki; Engel, James Douglas

    2016-09-01

    GATA3 is a zinc finger transcription factor that plays a crucial role in embryonic kidney development, while its precise functions in the adult kidney remain largely unexplored. Here, we demonstrate that GATA3 is specifically expressed in glomerular mesangial cells and plays a critical role in the maintenance of renal glomerular function. Newly generated Gata3 hypomorphic mutant mice exhibited neonatal lethality associated with severe renal hypoplasia. Normal kidney size was restored by breeding the hypomorphic mutant with a rescuing transgenic mouse line bearing a 662-kb Gata3 yeast artificial chromosome (YAC), and these animals (termed G3YR mice) survived to adulthood. However, most of the G3YR mice showed degenerative changes in glomerular mesangial cells, which deteriorated progressively during postnatal development. Consequently, the G3YR adult mice suffered severe renal failure. We found that the 662-kb Gata3 YAC transgene recapitulated Gata3 expression in the renal tubules but failed to direct sufficient GATA3 activity to mesangial cells. Renal glomeruli of the G3YR mice had significantly reduced amounts of platelet-derived growth factor receptor (PDGFR), which is known to participate in the development and maintenance of glomerular mesangial cells. These results demonstrate a critical role for GATA3 in the maintenance of mesangial cells and its absolute requirement for prevention of glomerular disease. PMID:27296697

  3. Telomerase-mediated life-span extension of human primary fibroblasts by human artificial chromosome (HAC) vector

    SciTech Connect

    Shitara, Shingo; Kakeda, Minoru; Nagata, Keiko; Hiratsuka, Masaharu; Sano, Akiko; Osawa, Kanako; Okazaki, Akiyo; Katoh, Motonobu; Kazuki, Yasuhiro; Oshimura, Mitsuo; Tomizuka, Kazuma

    2008-05-09

    Telomerase-mediated life-span extension enables the expansion of normal cells without malignant transformation, and thus has been thought to be useful in cell therapies. Currently, integrating vectors including the retrovirus are used for human telomerase reverse transcriptase (hTERT)-mediated expansion of normal cells; however, the use of these vectors potentially causes unexpected insertional mutagenesis and/or activation of oncogenes. Here, we established normal human fibroblast (hPF) clones retaining non-integrating human artificial chromosome (HAC) vectors harboring the hTERT expression cassette. In hTERT-HAC/hPF clones, we observed the telomerase activity and the suppression of senescent-associated SA-{beta}-galactosidase activity. Furthermore, the hTERT-HAC/hPF clones continued growing beyond 120 days after cloning, whereas the hPF clones retaining the silent hTERT-HAC senesced within 70 days. Thus, hTERT-HAC-mediated episomal expression of hTERT allows the extension of the life-span of human primary cells, implying that gene delivery by non-integrating HAC vectors can be used to control cellular proliferative capacity of primary cultured cells.

  4. Visualization of lymphatic vessels by Prox1-promoter directed GFP reporter in a bacterial artificial chromosome-based transgenic mouse

    PubMed Central

    Choi, Inho; Chung, Hee Kyoung; Ramu, Swapnika; Lee, Ha Neul; Kim, Kyu Eui; Lee, Sunju; Yoo, Jaehyuk; Choi, Dongwon; Lee, Yong Suk; Aguilar, Berenice

    2011-01-01

    Although the blood vessel-specific fluorescent transgenic mouse has been an excellent tool to study vasculogenesis and angiogenesis, a lymphatic-specific fluorescent mouse model has not been established to date. Here we report a transgenic animal model that expresses the green fluorescent protein under the promoter of Prox1, a master control gene in lymphatic development. Generated using an approximately 200-kb-long bacterial artificial chromosome harboring the entire Prox1 gene, this Prox1-green fluorescent protein mouse was found to faithfully recapitulate the expression pattern of the Prox1 gene in lymphatic endothelial cells and other Prox1-expressing organs, and enabled us to conveniently visualize detailed structure and morphology of lymphatic vessels and networks throughout development. Our data demonstrate that this novel transgenic mouse can be extremely useful for detection, imaging, and isolation of lymphatic vessels and monitoring wound-associated lymphangiogenesis. Together, this Prox1-green fluorescent protein transgenic mouse will be a great tool for the lymphatic research. PMID:20962325

  5. Functional characterization of Kaposi's sarcoma-associated herpesvirus small capsid protein by bacterial artificial chromosome-based mutagenesis

    SciTech Connect

    Sathish, Narayanan; Yuan Yan

    2010-11-25

    A systematic investigation of interactions amongst KSHV capsid proteins was undertaken in this study to comprehend lesser known KSHV capsid assembly mechanisms. Interestingly the interaction patterns of the KSHV small capsid protein, ORF65 suggested its plausible role in viral capsid assembly pathways. Towards further understanding this, ORF65-null recombinant mutants (BAC-{Delta}65 and BAC-stop65) employing a bacterial artificial chromosome (BAC) system were generated. No significant difference was found in both overall viral gene expression and lytic DNA replication between stable monolayers of 293T-BAC36 (wild-type) and 293T-BAC-ORF65-null upon induction with 12-O-tetradecanoylphorbol-13-acetate, though the latter released 30-fold fewer virions to the medium than 293T-BAC36 cells. Sedimentation profiles of capsid proteins of ORF65-null recombinant mutants were non-reflective of their organization into the KSHV capsids and were also undetectable in cytoplasmic extracts compared to noticeable levels in nuclear extracts. These observations collectively suggested the pivotal role of ORF65 in the KSHV capsid assembly processes.

  6. Process for assembly and transformation into Saccharomyces cerevisiae of a synthetic yeast artificial chromosome containing a multigene cassette to express enzymes that enhance xylose utilization designed for an automated pla

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A yeast artificial chromosome (YAC) containing a multigene cassette for expression of enzymes that enhance xylose utilization (xylose isomerase [XI] and xylulokinase [XKS]) was constructed and transformed into Saccharomyces cerevisiae to demonstrate feasibility as a stable protein expression system ...

  7. Comparative fluorescence in situ hybridization mapping of a 431-kb Arabidopsis thaliana bacterial artificial chromosome contig reveals the role of chromosomal duplications in the expansion of the Brassica rapa genome.

    PubMed Central

    Jackson, S A; Cheng, Z; Wang, M L; Goodman, H M; Jiang, J

    2000-01-01

    Comparative genome studies are important contributors to our understanding of genome evolution. Most comparative genome studies in plants have been based on genetic mapping of homologous DNA loci in different genomes. Large-scale comparative physical mapping has been hindered by the lack of efficient and affordable techniques. We report here the adaptation of fluorescence in situ hybridization (FISH) techniques for comparative physical mapping between Arabidopsis thaliana and Brassica rapa. A set of six bacterial artificial chromosomes (BACs) representing a 431-kb contiguous region of chromosome 2 of A. thaliana was mapped on both chromosomes and DNA fibers of B. rapa. This DNA fragment has a single location in the A. thaliana genome, but hybridized to four to six B. rapa chromosomes, indicating multiple duplications in the B. rapa genome. The sizes of the fiber-FISH signals from the same BACs were not longer in B. rapa than those in A. thaliana, suggesting that this genomic region is duplicated but not expanded in the B. rapa genome. The comparative fiber-FISH mapping results support that chromosomal duplications, rather than regional expansion due to accumulation of repetitive sequences in the intergenic regions, played the major role in the evolution of the B. rapa genome. PMID:11014828

  8. Isolation and characterization of transcribed sequences from a chromosome 16 hn-cDNA library and the physical mapping of genes and transcribed sequences using a high-resolution somatic cell panel of human chromosome 16

    SciTech Connect

    Whitmore, S.A.; Apostolou, S.; Lane, S.; Nancarrow, J.K.; Phillips, H.A.; Richards, R.I.; Sutherland, G.R.; Callen, D.F. )

    1994-03-15

    A hn-cDNA (heteronuclear complementary DNA) library was constructed from a mouse/human somatic cell hybrid, CY18, which contains chromosome 16 as the only human chromosome. Hexamer primers constructed from consensus 5[prime]intron splice sequences were used to generate cDNA from the immature unspliced mRNA. The resulting cDNA library was screened with a total human DNA probe to identify potential human clones. Rescreening was necessary, and use of a mouse-derived clone with homology to 7SL RNA proved successful in eliminating the majority of mouse clones. Thirteen clones had open reading frames, and of those, five showed homology to human sequences in Gen-Bank. Two clones had homology to random partially sequenced cDNAs, one clone was likely to be a GRP78 pseudogene, one clone mapped the PHKG2 gene to 16p11.2-16p12.1, and one clone had homology to human S-13 ribosomal protein. All clones except the latter were mapped to a high-resolution somatic cell panel. Although isolation of human chromosome 16 genes from this library was successful, it was apparent that cDNA synthesis was initiated at sites other than intron splice sites, presumably by mispairing of the hexamers. 31 refs., 4 figs., 1 tab.

  9. Cloning human herpes virus 6A genome into bacterial artificial chromosomes and study of DNA replication intermediates

    PubMed Central

    Borenstein, Ronen; Frenkel, Niza

    2009-01-01

    Cloning of large viral genomes into bacterial artificial chromosomes (BACs) facilitates analyses of viral functions and molecular mutagenesis. Previous derivations of viral BACs involved laborious recombinations within infected cells. We describe a single-step production of viral BACs by direct cloning of unit length genomes, derived from circular or head-to-tail concatemeric DNA replication intermediates. The BAC cloning is independent of intracellular recombinations and DNA packaging constraints. We introduced the 160-kb human herpes virus 6A (HHV-6A) genome into BACs by digesting the viral DNA replicative intermediates with the Sfil enzyme that cleaves the viral genome in a single site. The recombinant BACs contained also the puromycin selection gene, GFP, and LoxP sites flanking the BAC sequences. The HHV-6A-BAC vectors were retained stably in puromycin selected 293T cells. In the presence of irradiated helper virus, supplying most likely proteins enhancing gene expression they expressed early and late genes in SupT1 T cells. The method is especially attractive for viruses that replicate inefficiently and for viruses propagated in suspension cells. We have used the fact that the BAC cloning “freezes” the viral DNA replication intermediates to analyze their structure. The results revealed that HHV-6A-BACs contained a single direct repeat (DR) rather than a DR-DR sequence, predicted to arise by circularization of parental genomes with a DR at each terminus. HHV-6A DNA molecules prepared from the infected cells also contained DNA molecules with a single DR. Such forms were not previously described for HHV-6 DNA. PMID:19858479

  10. Yeast artificial chromosomes employed for random assembly of biosynthetic pathways and production of diverse compounds in Saccharomyces cerevisiae

    PubMed Central

    Naesby, Michael; Nielsen, Søren VS; Nielsen, Curt AF; Green, Trine; Tange, Thomas Ø; Simón, Ernesto; Knechtle, Philipp; Hansson, Anders; Schwab, Markus S; Titiz, Olca; Folly, Christophe; Archila, Roberto E; Maver, Milena; van Sint Fiet, Stephan; Boussemghoune, Thiamo; Janes, Michael; Kumar, A S Sathish; Sonkar, Shailendra P; Mitra, Partha P; Benjamin, V Ajai Kumar; Korrapati, Nimitha; Suman, Inala; Hansen, Esben H; Thybo, Tanja; Goldsmith, Neil; Sorensen, Alexandra Santana

    2009-01-01

    Background Natural products are an important source of drugs and other commercially interesting compounds, however their isolation and production is often difficult. Metabolic engineering, mainly in bacteria and yeast, has sought to circumvent some of the associated problems but also this approach is impeded by technical limitations. Here we describe a novel strategy for production of diverse natural products, comprising the expression of an unprecedented large number of biosynthetic genes in a heterologous host. Results As an example, genes from different sources, representing enzymes of a seven step flavonoid pathway, were individually cloned into yeast expression cassettes, which were then randomly combined on Yeast Artificial Chromosomes and used, in a single transformation of yeast, to create a variety of flavonoid producing pathways. Randomly picked clones were analysed, and approximately half of them showed production of the flavanone naringenin, and a third of them produced the flavonol kaempferol in various amounts. This reflected the assembly of 5–7 step multi-species pathways converting the yeast metabolites phenylalanine and/or tyrosine into flavonoids, normally only produced by plants. Other flavonoids were also produced that were either direct intermediates or derivatives thereof. Feeding natural and unnatural, halogenated precursors to these recombinant clones demonstrated the potential to further diversify the type of molecules that can be produced with this technology. Conclusion The technology has many potential uses but is particularly suited for generating high numbers of structurally diverse compounds, some of which may not be amenable to chemical synthesis, thus greatly facilitating access to a huge chemical space in the search for new commercially interesting compounds PMID:19678954

  11. Human Bacterial Artificial Chromosome (BAC) Transgenesis Fully Rescues Noradrenergic Function in Dopamine β-Hydroxylase Knockout Mice

    PubMed Central

    Cubells, Joseph F.; Schroeder, Jason P.; Barrie, Elizabeth S.; Manvich, Daniel F.; Sadee, Wolfgang; Berg, Tiina; Mercer, Kristina; Stowe, Taylor A.; Liles, L. Cameron; Squires, Katherine E.; Mezher, Andrew; Curtin, Patrick; Perdomo, Dannie L.; Szot, Patricia; Weinshenker, David

    2016-01-01

    Dopamine β-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE) in noradrenergic/adrenergic cells. DBH deficiency prevents NE production and causes sympathetic failure, hypotension and ptosis in humans and mice; DBH knockout (Dbh -/-) mice reveal other NE deficiency phenotypes including embryonic lethality, delayed growth, and behavioral defects. Furthermore, a single nucleotide polymorphism (SNP) in the human DBH gene promoter (-970C>T; rs1611115) is associated with variation in serum DBH activity and with several neurological- and neuropsychiatric-related disorders, although its impact on DBH expression is controversial. Phenotypes associated with DBH deficiency are typically treated with L-3,4-dihydroxyphenylserine (DOPS), which can be converted to NE by aromatic acid decarboxylase (AADC) in the absence of DBH. In this study, we generated transgenic mice carrying a human bacterial artificial chromosome (BAC) encompassing the DBH coding locus as well as ~45 kb of upstream and ~107 kb of downstream sequence to address two issues. First, we characterized the neuroanatomical, neurochemical, physiological, and behavioral transgenic rescue of DBH deficiency by crossing the BAC onto a Dbh -/- background. Second, we compared human DBH mRNA abundance between transgenic lines carrying either a “C” or a “T” at position -970. The BAC transgene drove human DBH mRNA expression in a pattern indistinguishable from the endogenous gene, restored normal catecholamine levels to the peripheral organs and brain of Dbh -/- mice, and fully rescued embryonic lethality, delayed growth, ptosis, reduced exploratory activity, and seizure susceptibility. In some cases, transgenic rescue was superior to DOPS. However, allelic variation at the rs1611115 SNP had no impact on mRNA levels in any tissue. These results indicate that the human BAC contains all of the genetic information required for tissue-specific, functional expression of DBH and can rescue all measured Dbh

  12. Human Bacterial Artificial Chromosome (BAC) Transgenesis Fully Rescues Noradrenergic Function in Dopamine β-Hydroxylase Knockout Mice.

    PubMed

    Cubells, Joseph F; Schroeder, Jason P; Barrie, Elizabeth S; Manvich, Daniel F; Sadee, Wolfgang; Berg, Tiina; Mercer, Kristina; Stowe, Taylor A; Liles, L Cameron; Squires, Katherine E; Mezher, Andrew; Curtin, Patrick; Perdomo, Dannie L; Szot, Patricia; Weinshenker, David

    2016-01-01

    Dopamine β-hydroxylase (DBH) converts dopamine (DA) to norepinephrine (NE) in noradrenergic/adrenergic cells. DBH deficiency prevents NE production and causes sympathetic failure, hypotension and ptosis in humans and mice; DBH knockout (Dbh -/-) mice reveal other NE deficiency phenotypes including embryonic lethality, delayed growth, and behavioral defects. Furthermore, a single nucleotide polymorphism (SNP) in the human DBH gene promoter (-970C>T; rs1611115) is associated with variation in serum DBH activity and with several neurological- and neuropsychiatric-related disorders, although its impact on DBH expression is controversial. Phenotypes associated with DBH deficiency are typically treated with L-3,4-dihydroxyphenylserine (DOPS), which can be converted to NE by aromatic acid decarboxylase (AADC) in the absence of DBH. In this study, we generated transgenic mice carrying a human bacterial artificial chromosome (BAC) encompassing the DBH coding locus as well as ~45 kb of upstream and ~107 kb of downstream sequence to address two issues. First, we characterized the neuroanatomical, neurochemical, physiological, and behavioral transgenic rescue of DBH deficiency by crossing the BAC onto a Dbh -/- background. Second, we compared human DBH mRNA abundance between transgenic lines carrying either a "C" or a "T" at position -970. The BAC transgene drove human DBH mRNA expression in a pattern indistinguishable from the endogenous gene, restored normal catecholamine levels to the peripheral organs and brain of Dbh -/- mice, and fully rescued embryonic lethality, delayed growth, ptosis, reduced exploratory activity, and seizure susceptibility. In some cases, transgenic rescue was superior to DOPS. However, allelic variation at the rs1611115 SNP had no impact on mRNA levels in any tissue. These results indicate that the human BAC contains all of the genetic information required for tissue-specific, functional expression of DBH and can rescue all measured Dbh deficiency

  13. Functional characterization of Kaposi's sarcoma-associated herpesvirus open reading frame K8 by bacterial artificial chromosome-based mutagenesis.

    PubMed

    Wang, Yan; Sathish, Narayanan; Hollow, Charles; Yuan, Yan

    2011-03-01

    The open reading frame K8 of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a basic leucine zipper (bZip) protein that binds to the origin of viral DNA replication and is an integral component of viral lytic DNA replication complex. Moreover, K8 physically interacts with replication and transcription activator (RTA) and represses its transactivation activity on several viral promoters. To investigate the role of this protein in viral life cycle, we constructed two K8-null recombinant mutant viruses (BAC-ΔK8 and BAC-stopK8) by using a bacterial artificial chromosome (BAC) system. Latent viral infection can be reconstituted in 293T and BJAB cells with wild-type and the K8-null recombinant viruses by introducing the cloned viral genomes into the cells. When the cells carrying these viruses were induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate, no significant difference was seen in overall viral gene expression between wild-type and K8-null viruses, with lytic DNA replication still active in the latter. However, 293T cells harboring K8-null mutant viruses, either BAC-ΔK8 or BAC-stopK8, displayed lower copy numbers of latent KSHV genome in comparison with wild-type viruses. Furthermore, although K8 deficiency appeared to not affect infectivity when K8-null viruses were used to infect 293T, primary human microvascular dermal endothelial and human foreskin fibroblast cells, they exhibited much lower viral genome copy numbers in all types of cell compared to wild-type viruses. Taken together, these data suggest a possible role of K8 in abortive lytic DNA replication occurring in early stages of de novo infection or in the maintenance of latent viral genomes. PMID:21159864

  14. A method for producing transgenic cells using a multi-integrase system on a human artificial chromosome vector.

    PubMed

    Yamaguchi, Shigeyuki; Kazuki, Yasuhiro; Nakayama, Yuji; Nanba, Eiji; Oshimura, Mitsuo; Ohbayashi, Tetsuya

    2011-01-01

    The production of cells capable of expressing gene(s) of interest is important for a variety of applications in biomedicine and biotechnology, including gene therapy and animal transgenesis. The ability to insert transgenes at a precise location in the genome, using site-specific recombinases such as Cre, FLP, and ΦC31, has major benefits for the efficiency of transgenesis. Recent work on integrases from ΦC31, R4, TP901-1 and Bxb1 phages demonstrated that these recombinases catalyze site-specific recombination in mammalian cells. In the present study, we examined the activities of integrases on site-specific recombination and gene expression in mammalian cells. We designed a human artificial chromosome (HAC) vector containing five recombination sites (ΦC31 attP, R4 attP, TP901-1 attP, Bxb1 attP and FRT; multi-integrase HAC vector) and de novo mammalian codon-optimized integrases. The multi-integrase HAC vector has several functions, including gene integration in a precise locus and avoiding genomic position effects; therefore, it was used as a platform to investigate integrase activities. Integrases carried out site-specific recombination at frequencies ranging from 39.3-96.8%. Additionally, we observed homogenous gene expression in 77.3-87.5% of colonies obtained using the multi-integrase HAC vector. This vector is also transferable to another cell line, and is capable of accepting genes of interest in this environment. These data suggest that integrases have high DNA recombination efficiencies in mammalian cells. The multi-integrase HAC vector enables us to produce transgene-expressing cells efficiently and create platform cell lines for gene expression. PMID:21390305

  15. Construction and Characterization of a Repetitive DNA Library in Parodontidae (Actinopterygii: Characiformes): A Genomic and Evolutionary Approach to the Degeneration of the W Sex Chromosome

    PubMed Central

    Oliveira, Jordana Inácio Nascimento; Nogaroto, Viviane; Almeida, Mara Cristina; Artoni, Roberto Ferreira; Cestari, Marta Margarete; Moreira-Filho, Orlando; Vicari, Marcelo Ricardo

    2014-01-01

    Abstract Repetitive DNA sequences, including tandem and dispersed repeats, comprise a large portion of eukaryotic genomes and are important for gene regulation, sex chromosome differentiation, and karyotype evolution. In Parodontidae, only the repetitive DNAs WAp and pPh2004 and rDNAs were previously studied using fluorescence in situ hybridization. This study aimed to build a library of repetitive DNA in Parodontidae. We isolated 40 clones using Cot-1; 17 of these clones exhibited similarity to repetitive DNA sequences, including satellites, minisatellites, microsatellites, and class I and class II transposable elements (TEs), from Danio rerio and other organisms. The physical mapping of the clones to chromosomes revealed the presence of a satellite DNA, a Helitron element, and degenerate short interspersed element (SINE), long interspersed element (LINE), and tc1-mariner elements on the sex chromosomes. Some clones exhibited dispersed signals; other sequences were not detected. The 5S rDNA was detected on an autosomal pair. These elements likely function in the molecular degeneration of the W chromosome in Parodontidae. Thus, the location of these elements on the chromosomes is important for understanding the function of these repetitive DNAs and for integrative studies with genome sequencing. The presented data demonstrate that an intensive invasion of TEs occurred during W sex chromosome differentiation in the Parodontidae. PMID:25122415

  16. Artificial Intelligence and Expert Systems: Will They Change the Library? Papers Presented at the Annual Clinic on Library Applications of Data Processing (27th, Urbana, Illinois, March 25-27, 1990). Illinois, March 25-27, 1990).

    ERIC Educational Resources Information Center

    Lancaster, F. W., Ed.; Smith, Linda C., Ed.

    Some of the 12 conference papers presented in this proceedings focus on the present and potential capabilities of artificial intelligence and expert systems as they relate to a wide range of library applications, including descriptive cataloging, technical services, collection development, subject indexing, reference services, database searching,…

  17. A 6-Mb yeast artificial chromosome contig and long-range physical map encompassing the region on chromosome 12q15 frequently rearranged in a variety of benign solid tumors

    SciTech Connect

    Schoenmakers, E.F.P.M.; Geurts, J.M.W.; Kools, P.F.J.; Mols, R.

    1995-10-10

    Cytogenetic analysis of a variety of benign solid tumors, among which uterine leiomyoma, lipoma, pleomorphic salivary gland adenoma, and pulmonary chondroid hamartoma, has indicated that these tumors often display chromosome breakpoints in region q13-q15 of chromosome 12. In previous studies, we have reported that these breakpoints map between locus D12S8 and the CHOP gene, the latter of which has been shown to be consistently rearranged in myxoid liposarcomas with t(12;16)(q13;p11). Here, we report directional chromosome walking studies starting from D12S8 and resulting in the construction of a YAC contig of about 6 Mb. This YAC contig, whose orientation on chromosome 12 was determined by double-color fluorescence in situ hybridization (FISH) analysis, has at least double coverage and consists of 75 overlapping YAC clones, all isolated from CEPH YAC libraries. Their insert sizes were estimated by contour-clamped homogeneous electric field (CHEF) gel electrophoresis. On the basis of YAC end-derived DNA markers and sequence-tagged sites (STSs), with an average spacing of approximately 70 kb, as well as restriction enzyme analysis, a long-range physical map was established for the 6-Mb DNA region of chromosome 12 covered by the YAC contig. Within the YAC contig, the relative positions of various known genes, an expressed sequence-tagged site, and a number of CEPH/Genethon polymorphic markers were determined. The latter data allow full integration of our mapping data with those obtained by CEPH/Genethon as well as those reported at the Second International Workshop on Human Chromosome 12 Mapping. Finally, this YAC contig constitutes the basis for the construction of a transcriptional map of this region and is likely to facilitate identification of genes involved in the formation of various benign solid tumor types. 56 refs., 1 fig., 2 tabs.

  18. Characterization of a BAC Library from Channel Catfish Ictalurus punctatus: Indications of High Rates of Evolution Among Teleost Genomes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The CHORI-212 bacterial artificial chromosome (BAC) library was constructed by cloning EcoRI/EcoRI partially digested DNA into the pTARBAC2.1 vector. The library has an average insert size of 161 kb, and provides 10.6-fold coverage of the channel catfish haploid genome. Screening of 32 genes using o...

  19. Characterization of a deep-coverage carrot (Daucus carota L.) BAC library and initial analysis of BAC-end sequences

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A 17.3-fold redundant bacterial artificial chromosome (BAC) library has been synthesized for carrot, the most-economically important member of the family Apiaceae. The library consists of 92,160 clones with an average insert size of 121 kb and ~ 2 % organellar DNA content. To provide an overview of ...

  20. Construction of a yeast artificial chromosome contig encompassing the human acidic fibroblast growth factor (FGF1) gene: Toward the cloning of the ANLL/MDS tumor-suppressor gene

    SciTech Connect

    Chiu, Ing-Ming; Gilmore, E.C.; Liu, Yang; Payson, R.A. )

    1994-02-01

    The region surrounding the human acidic fibroblast growth factor (FGF1) locus on chromosome 5q31 is of particular interest since it represents a critical region consistently lost in acute nonlymphocytic leukemia (ANLL) or myelodysplastic syndrome (MDS) patients who have a demonstrable deletion of the distal portion of the long arm of chromosome 5. It is proposed that an ANLL/MDS leukemia suppressor gene resides on 5q31. The authors have previously shown that the gene is most likely localized between FGF1 and PDGFRB/CSF1R loci. The region has also been linked to at least four other genetic diseases, Treacher Collins syndrome, diastrophic dysplasia, limb-girdle muscular dystrophy, and an autosomal dominant deafness, by linkage analysis. Here, they describe yeast artificial chromosomes (YAC) spanning 450 kb around the FGF1 gene. Six YAC clones were isolated from a human YAC library and their restriction enzyme maps were determined. The overlap of the clones with each other and with FGF1 cosmid and phage clones was characterized. Three of the YAC clones were found to contain the entire FGF1 gene, which spans more than 100 kb. Proximal and distal ends of several of these YAC clones were isolated for further overlap cloning. The proximal ends of both Y2 and Y4 were localized to previously isolated FGF1 DNA by sequence analysis. The distal ends of these two clones also hybridized to a human-hamster hybrid containing chromosome 5 as the only human genetic material. These results suggest that these YAC clones represent colinear DNA around the FGF1 locus. None of the YAC clones were found to contain the CD 14 and GRL genes, the closest known proximal and distal markers (relative to the centromere) to the FGF1 gene, respectively. This contig is useful for the overlap cloning of the 5q31 region and for reverse genetic strategies for the isolation of disease genes in the region. 46 refs., 7 figs., 5 tabs.

  1. Reliability Checks on the Indo-US Stellar Spectral Library Using Artificial Neural Networks and Principal Component Analysis

    NASA Astrophysics Data System (ADS)

    Singh, Harinder P.; Yuasa, Manabu; Yamamoto, Nawo; Gupta, Ranjan

    2006-02-01

    The Indo-US coudé feed stellar spectral library (CFLIB) made available to the astronomical community recently by Valdes et al. (2004, ApJS, 152, 251) contains spectra of 1273 stars in the spectral region 3460 to 9464Å at a high resolution of 1Å (FWHM) and a wide range of spectral types. Cross-checking the reliability of this database is an important and desirable exercise since a number of stars in this database have no known spectral types and a considerable fraction of stars has not so complete coverage in the full wavelength region of 3460-9464Å resulting in gaps ranging from a few Å to several tens of Å. We use an automated classification scheme based on Artificial Neural Networks (ANN) to classify all 1273 stars in the database. In addition, principal component analysis (PCA) is carried out to reduce the dimensionality of the data set before the spectra are classified by the ANN. Most importantly, we have successfully demonstrated employment of a variation of the PCA technique to restore the missing data in a sample of 300 stars out of the CFLIB.

  2. Development of BAC libraries and integrated physical mapping of human chromosome 22 using BACs. Annual report, July 1994--June 1995

    SciTech Connect

    Kim, U.J.; Shizuya, Hiroaki; Simon, M.I.

    1995-12-31

    BACs and fosmids are stable, nonchimeric, and highly representative cloning systems. BACs maintain large-fragment genomic inserts (100 to 300 kb) that are easily prepared for most types of experiments, including DNA sequencing. The authors have improved the methods for generating BACs and developed extensive BAC libraries. They have constructed human BAC libraries with more than 175,000 clones from male fibroblast and sperm, and a mouse BAC library with more than 200,000 clones. The authors are currently expanding human library with the aim of achieving total 50X coverage human genomic library using sperm samples from anonymous donors.

  3. Chromosome microdissection and cloning in human genome and genetic disease analysis

    SciTech Connect

    Kao, Faten Eleanor Roosevelt Inst. for Cancer Research, Denver, CO ); Yu, Jingwei )

    1991-03-01

    A procedure has been described for microdissection and microcloning of human chromosomal DNA sequences in which universal amplification of the dissected fragments by Mbo I linker adaptor and polymerase chain reaction is used. A very large library comprising 700,000 recombinant plasmid microclones from 30 dissected chromosomes of human chromosome 21 was constructed. Colony hybridization showed that 42% of the clones contained repetitive sequences and 58% contained single or low-copy sequences. The insert sizes generated by complete Mbo I cleavage ranged from 50 to 1,100 base pairs with a mean of 416 base pairs. Southern blot analysis of microclones from the library confirmed their human origin and chromosome 21 specificity. Some of these clones have also been regionally mapped to specific sites of chromosome 21 by using a regional mapping panel of cell hybrids. This chromosome microtechnology can generate large numbers of microclones with unique sequences from defined chromosomal regions and can be used for processes such as (i) isolating corresponding yeast artificial chromosome clones with large inserts, (ii) screening various cDNA libraries for isolating expressed sequences, and (iii) constructing region-specific libraries of the entire human genome. The studies described here demonstrate the power of this technology for high-resolution genome analysis and explicate their use in an efficient search for disease-associated genes localized to specific chromosomal regions.

  4. The human ovarian teratocarcinoma cell line PA-1 demonstrates a single translocation: analysis with fluorescence in situ hybridization, spectral karyotyping, and bacterial artificial chromosome microarray.

    PubMed

    Sarraf, Shireen; Tejada, Raphael; Abawi, Massih; Oberst, Michael; Dennis, Tom; Simon, Kelly Claire; Blancato, Jan

    2005-08-01

    Cell lines derived from tumors contain numerous chromosomal aberrations and are the focus of study in tumor evolution. The ovarian teratocarcinoma cell line PA-1 demonstrates a single chromosomal aberration: a reciprocal t(15;20)(p11.2;q11.2). A complete molecular genetic analysis was undertaken to characterize this cell line. The PA-1 cell line was studied with fluorescence in situ hybridization (FISH), spectral karyotyping (SKY), bacterial artificial chromosome (BAC) microarray, and Western blotting. Amplification of 20q is frequently implicated in both breast and ovarian cancer; this region contains a number of oncogenes including MDM2, ZNF217, and the ovarian tumor marker WFDC2 (alias HE4). FISH revealed gene amplification of AIB1 (now known as NCOA3) but not STK15 (now known as AURKA). Immunoblot analysis demonstrated 3.6-fold overexpression of the AIB1 protein product, but no elevation of the STK15. BAC cancer gene microarray analysis showed gene amplification of > or =1.20 for five oncogenes. The presence of a consistent single change in PA-1, the t(15;20)(p11.2;q11.2), suggests that the aberration is significant with respect to the transformation status of the cell line. This translocation appears to cause overexpression of AIB1 (and perhaps other proteins), which may provide an immortalizing effect on this cell line. PMID:16080959

  5. A Novel Ty1-Mediated Fragmentation Method for Native and Artificial Yeast Chromosomes Reveals That the Mouse Steel Gene Is a Hotspot for Ty1 Integration

    PubMed Central

    Dalgaard, J. Z.; Banerjee, M.; Curcio, M. J.

    1996-01-01

    We have developed a powerful new tool for the physical analysis of genomes called Ty1-mediated chromosomal fragmentation and have used the method to map 24 retrotransposon insertions into two different mouse-derived yeast artificial chromosomes (YACs). Expression of a plasmid-encoded GAL1:Ty1 fusion element marked with the retrotransposition indicator gene, ade2AI, resulted in a high fraction of cells that sustained a single Ty1 insertion marked with ADE2. Strains in which Ty1ADE2 inserted into a YAC were identified by cosegregation of the ADE2 gene with the URA3-marked YAC. Ty1ADE2 elements also carried a site for the endonuclease I-DmoI, which we demonstrate is not present anywhere in the yeast genome. Consequently, I-DmoI cleaved a single chromosome or YAC at the unique site of Ty1ADE2 insertion, allowing rapid mapping of integration events. Our analyses showed that the frequency of Ty1ADE2 integration into YACs is equivalent to or higher than that expected based on random insertion. Remarkably, the 50-kb transcription unit of the mouse Steel locus was shown to be a highly significant hotspot for Ty1 integration. The accessibility of mammalian transcription units to Ty1 insertion stands in contrast to that of yeast transcription units. PMID:8725218

  6. CHARACTERIZATION OF THREE MAIZE BAC LIBRARIES AND ANCHORING OF THE PHYSICAL MAP TO THE GENETIC MAP USING HIGH-DENSITY BAC FILTER HYBRIDIZATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three maize (Zea mays L.) bacterial artificial chromosome (BAC) libraries, HindIII, EcoRI and MboI, were constructed from inbred line B73 to minimize under-representation of certain genomic regions caused by the use of a single restriction enzyme library. High-density filter sets from all three lib...

  7. BAC Libraries from Wheat Chromosome 7D – Efficient Tool for Positional Cloning of Aphid Resistance Genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Positional cloning in bread wheat is a tedious task due to its huge genome size (~17 Gbp) and polyploid character. BAC libraries represent an essential tool for positional cloning. However, wheat BAC libraries comprise more than million clones, which make their screening very laborious. Here we pres...

  8. Selection of Specific Protein Binders for Pre-Defined Targets from an Optimized Library of Artificial Helicoidal Repeat Proteins (alphaRep)

    PubMed Central

    Chevrel, Anne; Graille, Marc; Fourati-Kammoun, Zaineb; Desmadril, Michel; van Tilbeurgh, Herman; Minard, Philippe

    2013-01-01

    We previously designed a new family of artificial proteins named αRep based on a subgroup of thermostable helicoidal HEAT-like repeats. We have now assembled a large optimized αRep library. In this library, the side chains at each variable position are not fully randomized but instead encoded by a distribution of codons based on the natural frequency of side chains of the natural repeats family. The library construction is based on a polymerization of micro-genes and therefore results in a distribution of proteins with a variable number of repeats. We improved the library construction process using a “filtration” procedure to retain only fully coding modules that were recombined to recreate sequence diversity. The final library named Lib2.1 contains 1.7×109 independent clones. Here, we used phage display to select, from the previously described library or from the new library, new specific αRep proteins binding to four different non-related predefined protein targets. Specific binders were selected in each case. The results show that binders with various sizes are selected including relatively long sequences, with up to 7 repeats. ITC-measured affinities vary with Kd values ranging from micromolar to nanomolar ranges. The formation of complexes is associated with a significant thermal stabilization of the bound target protein. The crystal structures of two complexes between αRep and their cognate targets were solved and show that the new interfaces are established by the variable surfaces of the repeated modules, as well by the variable N-cap residues. These results suggest that αRep library is a new and versatile source of tight and specific binding proteins with favorable biophysical properties. PMID:24014183

  9. Organization of the Bacillus subtilis 168 chromosome between kdg and the attachment site of the SP beta prophage: use of Long Accurate PCR and yeast artificial chromosomes for sequencing.

    PubMed

    Capuano, V; Galleron, N; Pujic, P; Sorokin, A; Ehrlich, S D

    1996-11-01

    Within the Bacillus subtilis genome sequencing project, the region between lysA and ilvA was assigned to our laboratory. In this report we present the sequence of the last 36 kb of this region, between the kdg operon and the attachment site of the SP beta prophage. A two-step strategy was used for the sequencing. In the first step, total chromosomal DNA was cloned in phage M13-based vectors and the clones carrying inserts from the target region were identified by hybridization with a cognate yeast artificial chromosome (YAC) from our collection. Sequencing of the clones allowed us to establish a number of contigs. In the second step the contigs were mapped by Long Accurate (LA) PCR and the remaining gaps closed by sequencing of the PCR products. The level of sequence inaccuracy due to LA PCR errors appeared to be about 1 in 10,000, which does not affect significantly the final sequence quality. This two-step strategy is efficient and we suggest that it can be applied to sequencing of longer chromosomal regions. The 36 kb sequence contains 38 coding sequences (CDSs), 19 of which encode unknown proteins. Seven genetic loci already mapped in this region, xpt, metB, ilvA, ilvD, thyB, dfrA and degR were identified. Eleven CDSs were found to display significant similarities to known proteins from the data banks, suggesting possible functions for some of the novel genes: cspD may encode a cold shock protein; bcsA, the first bacterial homologue of chalcone synthase; exol, a 5' to 3' exonuclease, similar to that of DNA polymerase I of Escherichia coli; and bsaA, a stress-response-associated protein. The protein encoded by yplP has homology with the transcriptional NifA-like regulators. The arrangement of the genes relative to possible promoters and terminators suggests 19 potential transcription units. PMID:8969496

  10. First Birth after Sperm Selection through Discontinuous Gradient Centrifugation and Artificial Insemination from a Chromosomal Translocation Carrier.

    PubMed

    Rouen, Alexandre; Hyon, Capucine; Balet, Richard; Joyé, Nicole; Cassuto, Nino Guy; Siffroi, Jean-Pierre

    2014-01-01

    Introduction. Balanced chromosomal carriers, though usually healthy, are confronted with recurrent spontaneous abortions and malformations in the offspring. Those are related to the transmission of an abnormal, chromosomally unbalanced genotype. We evidenced that the proportion of unbalanced spermatozoa can be significantly decreased through a sperm preparation process called discontinuous gradient centrifugation (DGC). We therefore started offering intrauterine inseminations with this procedure to couples with a male translocation carriers. Case Presentation. We report the case of a 37-year-old man carrying a t(3;10)(q25;p13) reciprocal translocation. He and his partner had had trouble conceiving for ten years and had four spontaneous abortions. DGC in this patient decreased the proportion of unbalanced spermatozoa from 63.6% to 52.3%. They were therefore offered intrauterine insemination with DGC, which eventually led to the birth of a healthy female child carrying the paternal translocation. Conclusion. We showed that translocation carriers could be offered intrauterine inseminations with DGC. Before this, the only two options were natural conception with prenatal diagnosis and termination of chromosomally unbalanced fetuses or preimplantation genetic diagnosis, which is a much heavier and costly procedure. We are currently offering this option through a multicentric program in France, and this is the first birth originating from it. PMID:24587925

  11. A MEQ Deleted Marek's Disease Virus Cloned as a Bacterial Artificial Chromosome is a Highly Efficacious Vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Marek’s disease virus (MDV) MEQ gene is essential for the T-cell lymphocytic infiltration of nerves and other organs seen in chickens with Marek’s disease (MD). In an earlier study, researchers used an overlapping cosmid clone library of MDV and demonstrated that deleting MEQ resulted in an exce...

  12. A 1.6-Mb contig of yeast artificial chromosomes around the human factor VIII gene reveals three regions homologous to probes for the DXS115 locus and two for the DXYS64 locus.

    PubMed Central

    Freije, D; Schlessinger, D

    1992-01-01

    Two yeast artificial chromosome (YAC) libraries were screened for probes in Xq28, around the gene for coagulation factor VIII (F8). A set of 30 YACs were recovered and assembled into a contig spanning at least 1.6 Mb from the DXYS64 locus to the glucose 6-phosphate dehydrogenase gene (G6PD). Overlaps among the YACs were determined by several fingerprinting techniques and by additional probes generated from YAC inserts by using Alu-vector or ligation-mediated PCR. Analysis of more than 30 probes and sequence-tagged sites (STSs) made from the region revealed the presence of several homologous genomic segments. For example, a probe for the DXYS64 locus, which maps less than 500 kb 5' of F8, detects a similar but not identical locus between F8 and G6PD. Also, a probe for the DXS115 locus detects at least three identical copies in this region, one in intron 22 of F8 and at least two more, which are upstream of the 5' end of the gene. Comparisons of genomic and YAC DNA suggest that the multiple loci are not created artifactually during cloning but reflect the structure of uncloned human DNA. On the basis of these data, the most likely order for the loci analyzed is tel-DXYS61-DXYS64-(DXS115-3-DXS115-2)-5'F8-(D XS115-1)-3'F8-G6PD. Images Figure 2 Figure 3 Figure 4 Figure 5 PMID:1609806

  13. HIV gene expression from intact proviruses positioned in bacterial artificial chromosomes at integration sites previously identified in latently infected T cells

    SciTech Connect

    Eipers, Peter G.; Salazar-Gonzalez, Jesus F.; Morrow, Casey D.

    2011-02-05

    HIV integration predominantly occurs in introns of transcriptionally active genes. To study the impact of the integration site on HIV gene expression, a complete HIV-1 provirus (with GFP as a fusion with Nef) was inserted into bacterial artificial chromosomes (BACs) at three sites previously identified in latent T cells of patients: topoisomerase II (Top2A), DNA methyltransferase 1 (DNMT1), or basic leucine transcription factor 2 (BACH2). Transfection of BAC-HIV into 293 T cells resulted in a fourfold difference in production of infectious HIV-1. Cell lines were established that contained BAC-Top2A, BAC-DNMT1, or BAC-BACH2, but only BAC-DNMT1 spontaneously produced virus, albeit at a low level. Stimulation with TNF-{alpha} resulted in virus production from four of five BAC-Top2A and all BAC-DNMT1 cell lines, but not from the BAC-BACH2 lines. The results of these studies highlight differences between integration sites identified in latent T cells to support virus production and reactivation from latency.

  14. Rapid and efficient introduction of a foreign gene into bacterial artificial chromosome-cloned varicella vaccine by Tn7-mediated site-specific transposition

    SciTech Connect

    Somboonthum, Pranee; Koshizuka, Tetsuo; Okamoto, Shigefumi; Matsuura, Masaaki; Gomi, Yasuyuki; Takahashi, Michiaki; Yamanishi, Koichi; Mori, Yasuko

    2010-06-20

    Using a rapid and reliable system based on Tn7-mediated site-specific transposition, we have successfully constructed a recombinant Oka varicella vaccine (vOka) expressing the mumps virus (MuV) fusion protein (F). The backbone of the vector was our previously reported vOka-BAC (bacterial artificial chromosome) genome. We inserted the transposon Tn7 attachment sequence, LacZ{alpha}-mini-attTn7, into the region between ORF12 and ORF13 to generate a vOka-BAC-Tn genome. The MuV-F expressing cassette was transposed into the vOka-BAC genome at the mini-attTn7 transposition site. MuV-F protein was expressed in recombinant virus, rvOka-F infected cells. In addition, the MuV-F protein was cleaved in the rvOka-F infected cells as in MuV-infected cells. The growth of rvOka-F was similar to that of the original recombinant vOka without the F gene. Thus, we show that Tn7-mediated transposition is an efficient method for introducing a foreign gene expression cassette into the vOka-BAC genome as a live virus vector.

  15. A 4.5-megabase yeast artificial chromosome contig from human chromosome 13q14.3 ordering 9 polymorphic microsatellites (22 sequence-tagged sites) tightly linked to the Wilson disease locus.

    PubMed Central

    White, A; Tomfohrde, J; Stewart, E; Barnes, R; Le Paslier, D; Weissenbach, J; Cavalli-Sforza, L; Farrer, L; Bowcock, A

    1993-01-01

    We have previously performed a genetic analysis of multiply affected families to map a locus responsible for Wilson disease (WND) to a 0.3-centimorgan (cM) region within chromosome 13q14.3, between D13S31 and D13S59. Here we describe the construction of a contig of approximately 4.5 Mb, which spans this region and extends from D13S25 to D13S59. This contig consists of 28 genomic yeast artificial chromosome (YAC) clones. Five critical crossover events have been defined in this interval in two unaffected (Centre d'Etudes du Polymorphisme Humain) and three WND families. The combination of sequence tagged site content mapping of YACs with both polymorphic and nonpolymorphic markers and recombination breakpoint mapping resulted in the following order of polymorphic markers: centromere-RB1-D13S25-AFM205vh2-D13S31-D13S22 7-D13S228-AFM238vc3-D13S133- AFM084xc5-D13S137-D13S169, D13S155-D13S59-telomere. The recombination/physical distance ratio varies from approximately 3000 kb per cM in the region between D13S31 and D13S25 to 6000 kb per cM in the region between D13S31 and D13S59. Three WND families exhibiting recombination between the disease locus and D13S31 or D13S59 were genotyped for additional markers in this region and further refined the location of the WND gene to between D13S155 and D13S133. Nine of the markers in this region of < 1 cM are polymorphic microsatellites (seven have observed heterozygosities of 70% or above) that will be extremely useful in prenatal and preclinical diagnosis of this disease. This physical map is an essential step in the isolation of the WND gene and is a framework for the identification of candidate genes. PMID:8234264

  16. Physical mapping of a large plant genome using global high-information content fingerprinting: a distal region of wheat chromosome 3DS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physical maps employing libraries of bacterial artificial chromosome (BAC) clones are essential for comparative genomics and sequencing of large and repetitive genomes such as those of wheat. We report the use of the Ae. tauschii, the diploid ancestor of the wheat D genome, for the construction of t...

  17. Physical mapping of a large plant genome using global high-information-content-fingerprinting: the distal region of the wheat ancestor Aegilops tauschii chromosome 3DS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Physical maps employing libraries of bacterial artificial chromosome (BAC) clones are essential for comparative genomics and sequencing of large and repetitive genomes such as those of the hexaploid bread wheat. The diploid ancestor of wheat genome, Aegilops tauschii, is used as a resource for wheat...

  18. De Novo Designed Proteins from a Library of Artificial Sequences Function in Escherichia Coli and Enable Cell Growth

    PubMed Central

    Fisher, Michael A.; McKinley, Kara L.; Bradley, Luke H.; Viola, Sara R.; Hecht, Michael H.

    2011-01-01

    A central challenge of synthetic biology is to enable the growth of living systems using parts that are not derived from nature, but designed and synthesized in the laboratory. As an initial step toward achieving this goal, we probed the ability of a collection of >106 de novo designed proteins to provide biological functions necessary to sustain cell growth. Our collection of proteins was drawn from a combinatorial library of 102-residue sequences, designed by binary patterning of polar and nonpolar residues to fold into stable 4-helix bundles. We probed the capacity of proteins from this library to function in vivo by testing their abilities to rescue 27 different knockout strains of Escherichia coli, each deleted for a conditionally essential gene. Four different strains – ΔserB, ΔgltA, ΔilvA, and Δfes – were rescued by specific sequences from our library. Further experiments demonstrated that a strain simultaneously deleted for all four genes was rescued by co-expression of four novel sequences. Thus, cells deleted for ∼0.1% of the E. coli genome (and ∼1% of the genes required for growth under nutrient-poor conditions) can be sustained by sequences designed de novo. PMID:21245923

  19. Genetic Analysis of Varicella-Zoster Virus ORF0 to ORF4 by Use of a Novel Luciferase Bacterial Artificial Chromosome System▿

    PubMed Central

    Zhang, Zhen; Rowe, Jenny; Wang, Weijia; Sommer, Marvin; Arvin, Ann; Moffat, Jennifer; Zhu, Hua

    2007-01-01

    To efficiently generate varicella-zoster virus (VZV) mutants, we inserted a bacterial artificial chromosome (BAC) vector in the pOka genome. We showed that the recombinant VZV (VZVBAC) strain was produced efficiently from the BAC DNA and behaved indistinguishably from wild-type virus. Moreover, VZV's cell-associated nature makes characterizing VZV mutant growth kinetics difficult, especially when attempts are made to monitor viral replication in vivo. To overcome this problem, we then created a VZV strain carrying the luciferase gene (VZVLuc). This virus grew like the wild-type virus, and the resulting luciferase activity could be quantified both in vitro and in vivo. Using PCR-based mutagenesis, open reading frames (ORF) 0 to 4 were individually deleted from VZVLuc genomes. The deletion mutant viruses appeared after transfection into MeWo cells, except for ORF4, which was essential. Growth curve analysis using MeWo cells and SCID-hu mice indicated that ORF1, ORF2, and ORF3 were dispensable for VZV replication both in vitro and in vivo. Interestingly, the ORF0 deletion virus showed severely retarded growth both in vitro and in vivo. The growth defects of the ORF0 and ORF4 mutants could be fully rescued by introducing wild-type copies of these genes back into their native genome loci. This work has validated and justified the use of the novel luciferase VZV BAC system to efficiently generate recombinant VZV variants and ease subsequent viral growth kinetic analysis both in vitro and in vivo. PMID:17581997

  20. Cloning of the Koi Herpesvirus Genome as an Infectious Bacterial Artificial Chromosome Demonstrates That Disruption of the Thymidine Kinase Locus Induces Partial Attenuation in Cyprinus carpio koi▿

    PubMed Central

    Costes, B.; Fournier, G.; Michel, B.; Delforge, C.; Raj, V. Stalin; Dewals, B.; Gillet, L.; Drion, P.; Body, A.; Schynts, F.; Lieffrig, F.; Vanderplasschen, A.

    2008-01-01

    Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial chromosome (BAC) clone that can be used to produce KHV recombinant strains. This goal was achieved by the insertion of a loxP-flanked BAC cassette into the thymidine kinase (TK) locus. This insertion led to a BAC plasmid that was stably maintained in bacteria and was able to regenerate virions when permissive cells were transfected with the plasmid. Reconstituted virions free of the BAC cassette but carrying a disrupted TK locus (the FL BAC-excised strain) were produced by the transfection of Cre recombinase-expressing cells with the BAC. Similarly, virions with a wild-type revertant TK sequence (the FL BAC revertant strain) were produced by the cotransfection of cells with the BAC and a DNA fragment encoding the wild-type TK sequence. Reconstituted recombinant viruses were compared to the wild-type parental virus in vitro and in vivo. The FL BAC revertant strain and the FL BAC-excised strain replicated comparably to the parental FL strain. The FL BAC revertant strain induced KHV infection in koi carp that was indistinguishable from that induced by the parental strain, while the FL BAC-excised strain exhibited a partially attenuated phenotype. Finally, the usefulness of the KHV BAC for recombination studies was demonstrated by the production of an ORF16-deleted strain by using prokaryotic recombination technology. The availability of the KHV BAC is an important advance that will allow the study of viral genes involved in KHV pathogenesis, as well as the production of attenuated recombinant candidate vaccines. PMID:18337580

  1. Functional Characterization of Kaposi's Sarcoma-Associated Herpesvirus Open Reading Frame K8 by Bacterial Artificial Chromosome-Based Mutagenesis▿ †

    PubMed Central

    Wang, Yan; Sathish, Narayanan; Hollow, Charles; Yuan, Yan

    2011-01-01

    The open reading frame K8 of Kaposi's sarcoma-associated herpesvirus (KSHV) encodes a basic leucine zipper (bZip) protein that binds to the origin of viral DNA replication and is an integral component of viral lytic DNA replication complex. Moreover, K8 physically interacts with replication and transcription activator (RTA) and represses its transactivation activity on several viral promoters. To investigate the role of this protein in viral life cycle, we constructed two K8-null recombinant mutant viruses (BAC-ΔK8 and BAC-stopK8) by using a bacterial artificial chromosome (BAC) system. Latent viral infection can be reconstituted in 293T and BJAB cells with wild-type and the K8-null recombinant viruses by introducing the cloned viral genomes into the cells. When the cells carrying these viruses were induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) and sodium butyrate, no significant difference was seen in overall viral gene expression between wild-type and K8-null viruses, with lytic DNA replication still active in the latter. However, 293T cells harboring K8-null mutant viruses, either BAC-ΔK8 or BAC-stopK8, displayed lower copy numbers of latent KSHV genome in comparison with wild-type viruses. Furthermore, although K8 deficiency appeared to not affect infectivity when K8-null viruses were used to infect 293T, primary human microvascular dermal endothelial and human foreskin fibroblast cells, they exhibited much lower viral genome copy numbers in all types of cell compared to wild-type viruses. Taken together, these data suggest a possible role of K8 in abortive lytic DNA replication occurring in early stages of de novo infection or in the maintenance of latent viral genomes. PMID:21159864

  2. (Developing a physical map of human chromosome 22)

    SciTech Connect

    Simon, M.I.

    1991-01-01

    We have developed bacterial F-factor based systems for cloning large fragments of human DNA in E. coli. In addition to large size, these systems are capable of maintaining human DNA with a high degree of stability. The cosmid size clones are called Fosmids and the clones containing larger inserts (100--200 kb) are called bacterial artificial chromosomes (BACs). The ultimate test of the effectiveness of cloning and mapping technology is the degree to which it can be efficiently applied to solve complex mapping problems. We, therefore, plan to use the large fragment cloning procedure as well as a variety of other approaches to generate a complete map of overlapping clones corresponding to human chromosome 22. We have thus far prepared two human chromosome 22 specific Fosmid libraries and we are in the process of constructing a chromosome 22 specific BAC library composed of fragments larger than 100 kb. We will further optimize the technology so that libraries of fragments larger than 200 kb can be readily prepared.

  3. [Developing a physical map of human chromosome 22]. Progress report

    SciTech Connect

    Simon, M.I.

    1991-12-31

    We have developed bacterial F-factor based systems for cloning large fragments of human DNA in E. coli. In addition to large size, these systems are capable of maintaining human DNA with a high degree of stability. The cosmid size clones are called Fosmids and the clones containing larger inserts (100--200 kb) are called bacterial artificial chromosomes (BACs). The ultimate test of the effectiveness of cloning and mapping technology is the degree to which it can be efficiently applied to solve complex mapping problems. We, therefore, plan to use the large fragment cloning procedure as well as a variety of other approaches to generate a complete map of overlapping clones corresponding to human chromosome 22. We have thus far prepared two human chromosome 22 specific Fosmid libraries and we are in the process of constructing a chromosome 22 specific BAC library composed of fragments larger than 100 kb. We will further optimize the technology so that libraries of fragments larger than 200 kb can be readily prepared.

  4. Mapping and ordered cloning of the human X chromosome

    SciTech Connect

    Caskey, C.T.; Nelson, D.L.

    1992-12-01

    Progress is reported on gathering X chromosome specific libraries and integrating those with the library produced in this project. Further studies on understanding Fragile X Syndrome and other hereditary diseases related to the X chromosome are described. (DT)

  5. Human Chromosome 21: Mapping of the chromosomes and cloning of cDNAs

    SciTech Connect

    Antonarakis, S.E.

    1991-09-01

    The objective of the research funded by DOE grant DE-FG02-89ER60857 from 6/15/89 to 8/31/91 was to contribute to the physical mapping of human chromosome 21 (HC21) by cloning large fragments of DNA into Yeast Artificial Chromosomes (YACs) and identify YACs that map on HC21. A total of 54 sequence tagged sites (STS) have been developed and mapped in our laboratory to HC21 and can be used as initial reference points for YAC identification and construction of overlapping clones. A small YAC library was constructed which is HC21 specific. DNA from somatic cell hybrid WAV17 or from flow-sorted HC21 was partially digested with EcoRI, ligated into vectors PJS97, PJS98, and YACs have been obtained with average size insert of more than 300 kb. This library has been deposited in D. Patterson's lab for the Joint YAC screening effort. Additional YAC libraries from ICI Pharmaceuticals or from Los Alamos National Laboratories have been screened with several STS and positive YACs have been identified. Work in progress includes screening of YAC libraries in order to construct overlapping clones, characterization of the cloning ends of YACs, characterization of additional STS and cloning of HC21 specific cDNAs. 15 refs., 2 figs., 5 tabs.

  6. Possible mechanisms responsible for absence of a retrotransposon family on a plant Y chromosome.

    PubMed

    Kubat, Zdenek; Zluvova, Jitka; Vogel, Ivan; Kovacova, Viera; Cermak, Tomas; Cegan, Radim; Hobza, Roman; Vyskot, Boris; Kejnovsky, Eduard

    2014-04-01

    Some transposable elements (TEs) show extraordinary variance in abundance along sex chromosomes but the mechanisms responsible for this variance are unknown. Here, we studied Ogre long terminal repeat (LTR) retrotransposons in Silene latifolia, a dioecious plant with evolutionarily young heteromorphic sex chromosomes. Ogre elements are ubiquitous in the S. latifolia genome but surprisingly absent on the Y chromosome. Bacterial artificial chromosome (BAC) library analysis and fluorescence in situ hybridization (FISH) were used to determine Ogre structure and chromosomal localization. Next generation sequencing (NGS) data were analysed to assess the transcription level and abundance of small RNAs. Methylation of Ogres was determined by bisulphite sequencing. Phylogenetic analysis was used to determine mobilization time and selection forces acting on Ogre elements. We characterized three Ogre families ubiquitous in the S. latifolia genome. One family is nearly absent on the Y chromosome despite all the families having similar structures and spreading mechanisms. We showed that Ogre retrotransposons evolved before sex chromosomes appeared but were mobilized after formation of the Y chromosome. Our data suggest that the absence of one Ogre family on the Y chromosome may be caused by 24-nucleotide (24-nt) small RNA-mediated silencing leading to female-specific spreading. Our findings highlight epigenetic silencing mechanisms as potentially crucial factors in sex-specific spreading of some TEs, but other possible mechanisms are also discussed. PMID:24456522

  7. A genomic-scale artificial microRNA library as a tool to investigate the functionally redundant gene space in Arabidopsis.

    PubMed

    Hauser, Felix; Chen, Wenxiao; Deinlein, Ulrich; Chang, Kenneth; Ossowski, Stephan; Fitz, Joffrey; Hannon, Gregory J; Schroeder, Julian I

    2013-08-01

    Traditional forward genetic screens are limited in the identification of homologous genes with overlapping functions. Here, we report the analyses and assembly of genome-wide protein family definitions that comprise the largest estimate for the potentially redundant gene space in Arabidopsis thaliana. On this basis, a computational design of genome-wide family-specific artificial microRNAs (amiRNAs) was performed using high-performance computing resources. The amiRNA designs are searchable online (http://phantomdb.ucsd.edu). A computationally derived library of 22,000 amiRNAs was synthesized in 10 sublibraries of 1505 to 4082 amiRNAs, each targeting defined functional protein classes. For example, 2964 amiRNAs target annotated DNA and RNA binding protein families and 1777 target transporter proteins, and another sublibrary targets proteins of unknown function. To evaluate the potential of an amiRNA-based screen, we tested 122 amiRNAs targeting transcription factor, protein kinase, and protein phosphatase families. Several amiRNA lines showed morphological phenotypes, either comparable to known phenotypes of single and double/triple mutants or caused by overexpression of microRNAs. Moreover, novel morphological and abscisic acid-insensitive seed germination mutants were identified for amiRNAs targeting zinc finger homeodomain transcription factors and mitogen-activated protein kinase kinase kinases, respectively. These resources provide an approach for genome-wide genetic screens of the functionally redundant gene space in Arabidopsis. PMID:23956262

  8. A yeast artificial chromosome contig that spans the RB1-D13S31 interval on human chromosome 13 and encompasses the frequently deleted region in B-cell chronic lymphocytic leukemia

    SciTech Connect

    Hawthorn, L.; Roberts, T.; Cowell, J.K.

    1995-12-10

    Abnormalities involving chromosome 13 have been a reported as the only cytogenetic change in B-cell chronic lymphocytic leukemia (BCLL). Deletions are the most common cytogenetic abnormality and always involve 13q14, but when translocations are seen, the consistent breakpoint is always in 13q14. It is now established that deletions, distal to the RB1 gene in 13q14, are invariably associated with these translocations. We have recently described the smallest such deletion from a series of rearrangements from these tumors isolated in somatic cell hybrids, which spans approximately 1 Mb. In this report, we present the results of a series of a chromosome walking experiments using YACs and have been able to span this small deletion, which must contain the gene that is frequently deleted in BCLL. Four probes from 13q14 (RB1-mgg15-D13S25-D13S31) were used to isolate corresponding YACs for each of the markers. The chromosomal location of these YACs was verified using FISH, which also demonstrated their nonchimeric nature. Vectorette end rescue was then used to demonstrate the overlap of the YACs and to isolate new clones to complete the contig. The extremes of the contig were shown to cross the chromosome 13 translocation breakpoints isolated in somatic cell hybrids that carry the derivatives of chromosome 13 involved in the smallest BCLL deletion. This YAC contig covers the entire deletion and will prove a valuable resource to begin isolating genes from this region. In addition, we have isolated YACs corresponding to the RB1 locus, which extends the contig over a 3.8-cM distance on the chromosome. 25 refs., 1 fig., 1 tab.

  9. A yeast artificial chromosome contig and NotI restriction map that spans the tumor suppressor gene(s) locus, 11q22.2-q23.3

    SciTech Connect

    Arai, Yasuhito; Hosoda, Fumie; Nakayama, Kyoko; Ohki, Misao

    1996-07-01

    Human chromosome 11q22-q23 is a pathologically important region in which a high level of loss of heterozygosity has been reported for breast, ovary, cervical, colon, and lung carcinomas, malignant melanomas, and hematologic malignancies. This strongly indicates that one or more tumor suppressor genes reside within the deleted region. In this report, we report the development of a contig map that covers most of the deleted regions found in these malignancies. The map comprises a contig of 66 overlapping yeast artificial chromosomes (YACs) and spans a region of 17 Mb from the PGR gene at 11q22.2 to the MLL gene at q23.3. In the process of screening the YACs, 50 new sequence-tagged site markers were developed from the termini of the YAC inserts. These markers were used for chromosome walking, and the data were then integrated into the contig map. NotI sites in the region. Using 22 of them, a NotI restriction map of the region from PGR to D11S939 was developed. This YAC contig will provide efficient tools for identification of the putative tumor suppressor gene(s). 49 refs., 3 figs., 2 tabs.

  10. Mice trisomic for a bacterial artificial chromosome with the single-minded 2 gene (Sim2) show phenotypes similar to some of those present in the partial trisomy 16 mouse models of Down syndrome.

    PubMed

    Chrast, R; Scott, H S; Madani, R; Huber, L; Wolfer, D P; Prinz, M; Aguzzi, A; Lipp, H P; Antonarakis, S E

    2000-07-22

    The Drosophila single-minded (sim) transcription factor, is a master regulator of fruitfly neurogenesis. Recently, we have cloned and mapped a human homolog of sim, SIM2, to chromosome 21 in the so-called 'Down syndrome chromosomal region'. Three copies of SIM2 may contribute to some Down syndrome (DS) phenotypes because of the mapping position function as transcriptional repressor, temporal and spatial expression pattern of mouse Sim2, and the potentially analogous role of human SIM2 to that of Drosophila sim during neurogenesis. In order to validate this hypothesis in vivo, we have created the first bacterial artificial chromosome transgenic mice overexpressing a gene possibly involved in DS with only one or two additional copies of mouse Sim2. The transgene was shown to be expressed in the same spatial pattern as the endogenous gene. The mice develop normally, are fertile and do not show detectable histopathological abnormalities. However, detailed analysis of their behavior revealed anxiety-related/reduced exploratory behaviour and sensitivity to pain, phenotypes similar to those also present in other partial trisomy 16 mouse models of DS. Our data therefore suggest that overexpression of SIM2 contributes to some of the complex DS phenotypes. PMID:10915774

  11. Repetitive Genomic Elements in a European Corn Borer, Ostrinia nubilalis, BAC Library were Indicated by BAC End Sequencing and Development of Sequence Tag Site Markers: Implications for Lepidopteran Genomic Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia, and a model system for insect olfaction and speciation. A bacterial artificial chromosome (BAC) library constructed for O. nubilalis contains 36,864 clones with estim...

  12. The Chromosome Microdissection and Microcloning Technique.

    PubMed

    Zhang, Ying-Xin; Deng, Chuan-Liang; Hu, Zan-Min

    2016-01-01

    Chromosome microdissection followed by microcloning is an efficient tool combining cytogenetics and molecular genetics that can be used for the construction of the high density molecular marker linkage map and fine physical map, the generation of probes for chromosome painting, and the localization and cloning of important genes. Here, we describe a modified technique to microdissect a single chromosome, paint individual chromosomes, and construct single-chromosome DNA libraries. PMID:27511173

  13. Amplification of chromosomal DNA in situ

    DOEpatents

    Christian, Allen T.; Coleman, Matthew A.; Tucker, James D.

    2002-01-01

    Amplification of chromosomal DNA in situ to increase the amount of DNA associated with a chromosome or chromosome region is described. The amplification of chromosomal DNA in situ provides for the synthesis of Fluorescence in situ Hybridization (FISH) painting probes from single dissected chromosome fragments, the production of cDNA libraries from low copy mRNAs and improved in Comparative Genomic Hybridization (CGH) procedures.

  14. Screening and chromosome localization of two cotton BAC clones.

    PubMed

    Cui, Xinglei; Liu, Fang; Liu, Yuling; Zhou, Zhongli; Wang, Chunying; Yanyan Zhao; Meng, Fei; Wang, Xingxing; Cai, Xiaoyan; Wang, Yuhong; Peng, Renhai; Wang, Kunbo

    2016-01-01

    Two bacterial artificial chromosome (BAC) clones (350B21 and 299N22) of Pima 90-53 cotton [Gossypium barbadense Linnaeus, 1753 (2n=4x=52)] were screened from a BAC library using SSR markers. Strong hybridization signals were detected at terminal regions of all A genome (sub-genome) chromosomes, but were almost absent in D genome (sub-genome) chromosomes with BAC clone 350B21 as the probe. The results indicate that specific sequences, which only exist at the terminal parts of A genome (sub-genome) chromosomes with a huge repeat number, may be contained in BAC clone 350B21. When utilizing FISH with the BAC clone 299N22 as probe, a pair of obvious signals was detected on chromosome 13 of D genome (sub-genome), while strong dispersed signals were detected on all A genome (sub-genome) chromosomes. The results showed that peculiar repetitive sequence, which was distributed throughout all A genome (sub-genome) chromosomes, may exist in BAC clone 299N22. The absence of the repetitive sequences, which exist in the two BAC clones, in D genome may account for the genome-size variation between A and D genomes. In addition, the microcolinearity analysis of the clone 299N22 and its homologous region on Gossypium raimondii Ulbrich, 1932 chromosome 13 (D513) indicated that the clone 299N22 might come from A sub-genome of sea island cotton (Gossypium barbadense), and a huge number of small deletions, illegitimate recombination, translocation and rearrangements may have occurred during the genus evolution. The two BAC clones studied here can be used as cytological markers but will be also be helpful to research in cotton genome evolution and comparative genomics. PMID:27186333

  15. Screening and chromosome localization of two cotton BAC clones

    PubMed Central

    Cui, Xinglei; Liu, Fang; Liu, Yuling; Zhou, Zhongli; Wang, Chunying; Yanyan Zhao; Meng, Fei; Wang, Xingxing; Cai, Xiaoyan; Wang, Yuhong; Peng, Renhai; Wang, Kunbo

    2016-01-01

    Abstract Two bacterial artificial chromosome (BAC) clones (350B21 and 299N22) of Pima 90-53 cotton [Gossypium barbadense Linnaeus, 1753 (2n=4x=52)] were screened from a BAC library using SSR markers. Strong hybridization signals were detected at terminal regions of all A genome (sub-genome) chromosomes, but were almost absent in D genome (sub-genome) chromosomes with BAC clone 350B21 as the probe. The results indicate that specific sequences, which only exist at the terminal parts of A genome (sub-genome) chromosomes with a huge repeat number, may be contained in BAC clone 350B21. When utilizing FISH with the BAC clone 299N22 as probe, a pair of obvious signals was detected on chromosome 13 of D genome (sub-genome), while strong dispersed signals were detected on all A genome (sub-genome) chromosomes. The results showed that peculiar repetitive sequence, which was distributed throughout all A genome (sub-genome) chromosomes, may exist in BAC clone 299N22. The absence of the repetitive sequences, which exist in the two BAC clones, in D genome may account for the genome-size variation between A and D genomes. In addition, the microcolinearity analysis of the clone 299N22 and its homologous region on Gossypium raimondii Ulbrich, 1932 chromosome 13 (D513) indicated that the clone 299N22 might come from A sub-genome of sea island cotton (Gossypium barbadense), and a huge number of small deletions, illegitimate recombination, translocation and rearrangements may have occurred during the genus evolution. The two BAC clones studied here can be used as cytological markers but will be also be helpful to research in cotton genome evolution and comparative genomics. PMID:27186333

  16. Chromosomal Conditions

    MedlinePlus

    ... 150 babies is born with a chromosomal condition. Down syndrome is an example of a chromosomal condition. Because ... all pregnant women be offered prenatal tests for Down syndrome and other chromosomal conditions. A screening test is ...

  17. Construction and characterization of two bacterial artificial chromosome libraries of pea (Pisum sativum L.) for the isolation of economically important genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pea (Pisum sativum L.) has a genome of about 4 Gbp that appears to share conserved synteny with model legumes having genomes of 0.2-0.4 Gbp despite extensive intergenic expansion. Pea plant inventory (PI) 269818 has been used to introgress genetic diversity into the cultivated germplasm pool. The ai...

  18. Mapping and ordered cloning of the human X chromosome. Progress report, September 1991--November 1992

    SciTech Connect

    Caskey, C.T.; Nelson, D.L.

    1992-12-01

    Progress is reported on gathering X chromosome specific libraries and integrating those with the library produced in this project. Further studies on understanding Fragile X Syndrome and other hereditary diseases related to the X chromosome are described. (DT)

  19. Molecular cytotaxonomy of primates by chromosomal in situ suppression hybridization.

    PubMed

    Wienberg, J; Jauch, A; Stanyon, R; Cremer, T

    1990-10-01

    A new strategy for analyzing chromosomal evolution in primates is presented using chromosomal in situ suppression (CISS) hybridization. Biotin-labeled DNA libraries from flow-sorted human chromosomes are hybridized to chromosome preparations of catarrhines, platyrrhines, and prosimians. By this approach rearrangements of chromosomes that occurred during hominoid evolution are visualized directly at the level of DNA sequences, even in primate species with pronounced chromosomal shuffles. PMID:2249853

  20. Construction and characterization of a BAC library for the molecular dissection of a single wild beet centromere and sugar beet (Beta vulgaris) genome analysis.

    PubMed

    Gindullis, F; Dechyeva, D; Schmidt, T

    2001-10-01

    We have constructed a sugar beet bacterial artificial chromosome (BAC) library of the chromosome mutant PRO1. This Beta vulgaris mutant carries a single chromosome fragment of 6-9 Mbp that is derived from the wild beet Beta procumbens and is transmitted efficiently in meiosis and mitosis. The library consists of 50,304 clones, with an average insert size of 125 kb. Filter hybridizations revealed that approximately 3.1% of the clones contain mitochondrial or chloroplast DNA. Based on a haploid genome size of 758 Mbp, the library represents eight genome equivalents. Thus, there is a greater than 99.96% probability that any sequence of the PROI genome can be found in the library. Approximately 0.2% of the clones hybridized with centromeric sequences of the PRO1 minichromosome. Using the identified BAC clones in fluorescence in situ hybridization experiments with PRO1 and B. procumbens chromosome spreads, their wild-beet origin and centromeric localization were demonstrated. Comparative Southern hybridization of pulsed-field separated PROI DNA and BAC inserts indicate that the centromeric region of the minichromosome is represented by overlapping clones in the library. Therefore, the PRO1 BAC library provides a useful tool for the characterization of a single plant centromere and is a valuable resource for sugar beet genome analysis. PMID:11681609

  1. BAC libraries of Triticum urartu, Aegilops speltoides and Ae. tauschii, the diploid ancestors of polyploid wheat.

    PubMed

    Akhunov, E D; Akhunova, A R; Dvorák, J

    2005-11-01

    Triticum urartu, Aegilops speltoides and Ae. tauschii are respectively the immediate diploid sources, or their closest relatives, of the A, B and D genomes of polyploid wheats. Here we report the construction and characterization of arrayed large-insert libraries in a bacterial artificial chromosome (BAC) vector, one for each of these diploid species. The libraries are equivalent to 3.7, 5.4 and 4.1 of the T. urartu, Ae. speltoides, Ae. tauschii genomes, respectively. The predicted levels of genome coverage were confirmed by library hybridization with single-copy genes. The libraries were used to estimate the proportion of known repeated nucleotide sequences and gene content in each genome by BAC-end sequencing. Repeated sequence families previously detected in Triticeae accounted for 57, 61 and 57% of the T. urartu, Ae. speltoides and Ae. tauschii genomes, and coding regions accounted for 5.8, 4.5 and 4.8%, respectively. PMID:16177898

  2. Construction and characterization of a bovine BAC library with four genome-equivalent coverage.

    PubMed

    Eggen, A; Gautier, M; Billaut, A; Petit, E; Hayes, H; Laurent, P; Urban, C; Pfister-Genskow, M; Eilertsen, K; Bishop, M D

    2001-01-01

    A bovine artificial chromosome (BAC) library of 105 984 clones has been constructed in the vector pBeloBAC11 and organized in 3-dimension pools and high density membranes for screening by PCR and hybridization. The average insert size, determined after analysis of 388 clones, was estimated at 120 kb corresponding to a four genome coverage. Given the fact that a male was used to construct the library, the probability of finding any given autosomal and X or Y locus is respectively 0.98 and 0.86. The library was screened for 164 microsatellite markers and an average of 3.9 superpools was positive for each PCR system. None of the 50 or so BAC clones analysed by FISH was chimeric. This BAC library increases the international genome coverage for cattle to around 28 genome equivalents and extends the coverage of the ruminant genomes available at the Inra resource center to 15 genome equivalents. PMID:11712974

  3. Genetic and physical mapping of the bovine X chromosome.

    PubMed

    Yeh, C C; Taylor, J F; Gallagher, D S; Sanders, J O; Turner, J W; Davis, S K

    1996-03-01

    Three hundred eighty reciprocal backcross and F(2) full sib progeny from 33 families produced by embryo transfer from 77 Angus (Bos taurus), Brahman (Bos indicus), and F1 parents and grandparents were used to construct genetic maps of the bovine X and Y chromosomes. Ml individuals were scored for 15 microsatellite loci, with an average of 608 informative meioses per locus. The length of the bovine X chromosome genetic map was 118.7 cM (female only) and of the pseudoautosomal region was 13.0 cM (male only). The 15-marker framework map in Kosambi centimorgans is [BM6017-6.1 -TGLA89-35.8-TEXAN13-3.4-TGLA128-1.3 -BM2713 -21.1 -BM4604-2.4-BR215 - 12.9-TGLA68-10.0-BM4321 - 1.0-HEL14-4.9-TGLA15-2.3-INRA12O- 12.5-TGLA325- 1.6-MAF45-3.2-INRA3O], with an average interval of 7.91 cM. Clones containing pseudoautosomal or sex-linked microsatellites were isolated from a bovine bacterial artificial chromosome library and were physically mapped to bovine metaphase chromosomes by fluorescence in situ hybridization to orient the X and Y chromosome maps. BAC57, containing the pseudoautosomal microsatellite INRA3O, mapped to the distal end of the long arm of the X chromosome at q42-ter and to the short arm of the Y chromosome at p13-ter. This confirms the published assignment of this region to Ypl2-ter, but challenges the published assignment of Xpl4-ter and thus reorients the X chromosome physical map. BAC2O4, containing the X-linked microsatellite BM4604, mapped to the middle of the long arm of the X chromosome at q26-q31. The position of the physically mapped markers indicates either a lack of microsatellite markers for a large (30 to 50 cM) region of the short arm of the X chromosome or heterogeneity of recombination along the X chromosome. PMID:8833151

  4. Identification of a yeast artificial chromosome clone spanning a translocation breakpoint at 7q32.1 in a Smith-Lemli-Opitz syndrome patient.

    PubMed Central

    Alley, T L; Gray, B A; Lee, S H; Scherer, S W; Tsui, L C; Tint, G S; Williams, C A; Zori, R; Wallace, M R

    1995-01-01

    Smith-Lemli-Opitz syndrome (SLOS) is a mental retardation/multiple congenital anomaly syndrome. The gene(s) involved has not been mapped or cloned, but, recently, a biochemical abnormality in cholesterol biosynthesis has been shown to occur in most SLOS patients. The defect is suspected to occur in the penultimate step of the cholesterol pathway, involving the enzyme 7-dehydrocholesterol reductase, which has not been isolated. On the basis of the hypothesis that a de novo balanced translocation [t(7;20)(q32.1;q13.2)] in an SLOS patient directly interrupts the SLOS gene, positional cloning techniques are being employed to localize and identify the SLOS gene. We report the identification of a chromosome 7-specific YAC that spans the translocation breakpoint, as detected by FISH. This is the first study narrowing a candidate SLOS region and placing it on physical and genetic maps of the human genome. Images Figure 1 PMID:7762564

  5. [Chromosomal organization of the genomes of small-chromosome plants].

    PubMed

    Muravenko, O V; Zelenin, A V

    2009-11-01

    An effective approach to study the chromosome organization in genomes of plants with small chromosomes and/or with low-informative C-banding patterns was developed in the course of investigation of the karyotypes of cotton plant, camomile, flax, and pea. To increase the resolving power of chromosome analysis, methods were worked out for revealing early replication patterns on chromosomes and for artificial impairment of mitotic chromosome condensation with the use of a DNA intercalator, 9-aminoacridine (9-AMA). To estimate polymorphism of the patterns of C-banding of small chromosomes on preparations obtained with the use of 9-AMA, it is necessary to choose a length interval that must not exceed three average sizes of metaphase chromosomes without the intercalator. The use of 9-AMA increases the resolution of differential C- and OR-banding and the precision of physical chromosome mapping by the FISH method. Of particular importance in studying small chromosomes is optimization of the computer-aided methods used to obtain and process chromosome images. The complex approach developed for analysis of the chromosome organization in plant genomes was used to study the karyotypes of 24 species of the genus Linum L. It permitted their chromosomes to be identified for the first time, and, in addition, B chromosomes were discovered and studied in the karyotypes of the species of the section Syllinum. By similarity of the karyotypes, the studied flax species were distributed in eight groups in agreement with the clusterization of these species according to the results of RAPD analysis performed in parallel. Systematic positions and phylogenetic relationships of the studied flax species were verified. Out results can serve as an important argument in favour of the proposal to develop a special program for sequencing the genome of cultivated flax (L. usitatissimum L.), which is a major representative of small-chromosome species. PMID:20058798

  6. Preparation and characterization of a 3-fold redundant human PAC library

    SciTech Connect

    Guan, X.; Chen, C.; Frengen, E.

    1994-09-01

    Recently, we have developed new procedures for the cloning of large DNA fragments using a bacteriophage P1-derived vector, pCYPAC1. In view of the large sizes (up to 400 kb clones have been observed) and the single copy mode of maintenance, we have designated our clones as {open_quotes}PACs{close_quotes} for {open_quotes}P1-derived artificial chromosomes{close_quotes}. Our subsequent efforts have focused on the construction of a large human PAC library from MboI digested human DNA (from white blood cells). About 120,000 PAC clones have been picked into 312 microtiter dishes of 384 wells. Preliminary characterization has revealed that the insert containing clones have average inserts of 110-120 kb and that the library has approximately 27% empty clones (vector without insert). Based on the average insert size and the total number of recombinant clones, we estimate that the library has 3-fold genome redundancy. This estimate is consistent with results obtained by screening of the library: 18 STS markers detect 52 corresponding clones and 6 unique probes find 20 positives. The library is expanded to a final size of 6- to 8-fold genome redundancy and is also being characterized with by fluorescent in situ hybridization and chromosome-walking procedures. Copies of the arrayed library are being distributed.

  7. Construction of chromosome markers from the Lake Victoria cichlid Paralabidochromis chilotes and their application to comparative mapping.

    PubMed

    Kuroiwa, A; Terai, Y; Kobayashi, N; Yoshida, K; Suzuki, M; Nakanishi, A; Matsuda, Y; Watanabe, M; Okada, N

    2014-01-01

    Cichlid fishes in the African Great Lakes are known as a spectacular example of adaptive radiation in vertebrates. Four linkage maps have been constructed to identify the genes responsible for adaptation and speciation, and the genetic linkages of those genes are assumed to play an important role during adaptive evolution. However, it is difficult to analyze such linkages because the linkage groups of one species do not match well with those of the other species. Chromosome markers are a powerful tool for the direct identification of linkage homology between different species. We used information about the linkage map of the Lake Malawi cichlid (Labeotropheus fuelleborni/Metriaclima zebra) to isolate bacterial artificial chromosome (BAC) clones from the BAC library of Paralabidochromis chilotes, Lake Victoria. We identified 18 of 22 P. chilotes chromosomes by single- and multi-color BAC fluorescence in situ hybridization using 19 BAC clones. Comparative mapping with the chromosome markers of P. chilotes in Astatotilapia burtoni (2n = 40) from Lake Tanganyika revealed the chromosome rearrangements that have occurred in this lineage. These chromosome markers will be useful for delineating the process of genome and chromosome evolution in African species. PMID:24217467

  8. In Pursuit of Artificial Intelligence.

    ERIC Educational Resources Information Center

    Watstein, Sarah; Kesselman, Martin

    1986-01-01

    Defines artificial intelligence and reviews current research in natural language processing, expert systems, and robotics and sensory systems. Discussion covers current commercial applications of artificial intelligence and projections of uses and limitations in library technical and public services, e.g., in cataloging and online information and…

  9. Process for Assembly and Transformation into Saccharomyces cerevisiae of a Synthetic Yeast Artificial Chromosome Containing a Multigene Cassette to Express Enzymes That Enhance Xylose Utilization Designed for an Automated Platform.

    PubMed

    Hughes, Stephen R; Cox, Elby J; Bang, Sookie S; Pinkelman, Rebecca J; López-Núñez, Juan Carlos; Saha, Badal C; Qureshi, Nasib; Gibbons, William R; Fry, Michelle R; Moser, Bryan R; Bischoff, Kenneth M; Liu, Siqing; Sterner, David E; Butt, Tauseef R; Riedmuller, Steven B; Jones, Marjorie A; Riaño-Herrera, Néstor M

    2015-12-01

    A yeast artificial chromosome (YAC) containing a multigene cassette for expression of enzymes that enhance xylose utilization (xylose isomerase [XI] and xylulokinase [XKS]) was constructed and transformed into Saccharomyces cerevisiae to demonstrate feasibility as a stable protein expression system in yeast and to design an assembly process suitable for an automated platform. Expression of XI and XKS from the YAC was confirmed by Western blot and PCR analyses. The recombinant and wild-type strains showed similar growth on plates containing hexose sugars, but only recombinant grew on D-xylose and L-arabinose plates. In glucose fermentation, doubling time (4.6 h) and ethanol yield (0.44 g ethanol/g glucose) of recombinant were comparable to wild type (4.9 h and 0.44 g/g). In whole-corn hydrolysate, ethanol yield (0.55 g ethanol/g [glucose + xylose]) and xylose utilization (38%) for recombinant were higher than for wild type (0.47 g/g and 12%). In hydrolysate from spent coffee grounds, yield was 0.46 g ethanol/g (glucose + xylose), and xylose utilization was 93% for recombinant. These results indicate introducing a YAC expressing XI and XKS enhanced xylose utilization without affecting integrity of the host strain, and the process provides a potential platform for automated synthesis of a YAC for expression of multiple optimized genes to improve yeast strains. PMID:25720598

  10. Alphoid satellite DNA is tightly associated with centromere antigens in human chromosomes throughout the cell cycle

    SciTech Connect

    Masumoto, Hiroshi; Sugimoto, Kenji; Okazaki, Tuneko )

    1989-03-01

    In this study, the authors have examined a DNA element specific to the centromere domain of human chromosomes. Purified HeLa chromosomes were digested with the restriction enzyme Sau3AI and fractionated by sedimentation through a sucrose gradient. Fractions showing antigenicity to anticentromere (kinetochore) serum obtained from a scleroderma CREST patient were used to construct a DNA library. From this library they found one clone which has specifically hybridized to the centromere domain of metaphase chromosomes using a biotinylated probe DNA and FITC-conjugated avidin. The clone contained a stretch of alphoid DNA dimer. To determine precisely the relative location of the alphoid DNA stretch and the centromere antigen, a method was developed to carry out in situ hybridization of DNA and indirect immunofluorescent staining of antigen on the same cell preparation. Using this method, they have found perfect overlapping of the alphoid DNA sites with the centromere antigen in both metaphase chromosomes and nuclei at various stages in the cell cycle. They have also observed this exact correlation at the attachment sites of artificially extended sister chromatids. These results suggest the possibility that alphoid DNA repeats are a key component of kinetochore structure.

  11. Losing Libraries, Saving Libraries

    ERIC Educational Resources Information Center

    Miller, Rebecca

    2010-01-01

    This summer, as public libraries continued to get budget hit after budget hit across the country, several readers asked for a comprehensive picture of the ravages of the recession on library service. In partnership with 2010 Movers & Shakers Laura Solomon and Mandy Knapp, Ohio librarians who bought the Losing Libraries domain name, "LJ" launched…

  12. Chromosome specific repetitive DNA sequences

    DOEpatents

    Moyzis, Robert K.; Meyne, Julianne

    1991-01-01

    A method is provided for determining specific nucleotide sequences useful in forming a probe which can identify specific chromosomes, preferably through in situ hybridization within the cell itself. In one embodiment, chromosome preferential nucleotide sequences are first determined from a library of recombinant DNA clones having families of repetitive sequences. Library clones are identified with a low homology with a sequence of repetitive DNA families to which the first clones respectively belong and variant sequences are then identified by selecting clones having a pattern of hybridization with genomic DNA dissimilar to the hybridization pattern shown by the respective families. In another embodiment, variant sequences are selected from a sequence of a known repetitive DNA family. The selected variant sequence is classified as chromosome specific, chromosome preferential, or chromosome nonspecific. Sequences which are classified as chromosome preferential are further sequenced and regions are identified having a low homology with other regions of the chromosome preferential sequence or with known sequences of other family me This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  13. Positional cloning of the hereditary renal carcinoma 3; 8 chromosome translocation breakpoint

    SciTech Connect

    Boldog, F.L.; Nilsson, A.S.; Drabkin, H.A. ); Gemmill, R.M. ); Wilke, C.M.; Glover, T.W.; Chandrasekharappa, S.C. ); Brown, R.S. ); Li, F.P. )

    1993-09-15

    The chromosome (p14.2;q24.1) translocation t(3;8) has been associated with hereditary renal cancer in one family. Based on cytogenetic analysis and loss-of-heterozygosity experiments, the 3p14 region has been independently implicated as harboring a tumor suppressor gene critical to kidney and lung cancer development. The 3p14.2 region also contains FRA3B, the most sensititive fragile site induced by aphidicolin. A chromosome 3 probe, R7K145, derived from a radiation-reduced hybrid was positioned between the t(3;8) breakpoint and an aphidicolin-induced 3p14 breakpoint. A yeast artificial chromosome (YAC) contig containing R7K145 was developed that crossed the aphidicolin-induced breakpoint on its telomeric side. A subsequent chromosome walk identified a YAC that crossed the 3;8 translocation breakpoint. A [lambda] sublibrary allowed isolation of clones spanning the rearrangement. Unique and evolutionarily conserved DNA sequences were used to screen a kidney cDNA library. The authors have identified a gene, referred to as HRCA1 (hereditary renal cancer associated 1), that maps immediately adjacent to the breakpoint. On the basis of its chromosomal position, HRCA1 may be a candidate tumor suppressor gene. 42 refs., 5 figs.

  14. Isolation and characterization of bovine herpesvirus 4 (BoHV-4) from a cow affected by post partum metritis and cloning of the genome as a bacterial artificial chromosome

    PubMed Central

    Donofrio, Gaetano; Franceschi, Valentina; Capocefalo, Antonio; Cavirani, Sandro; Sheldon, Iain Martin

    2009-01-01

    Background Bovine herpesvirus 4 (BoHV-4) is a gammaherpesvirus with a Worldwide distribution in cattle and is often isolated from the uterus of animals with postpartum metritis or pelvic inflammatory disease. Virus strain adaptation to an organ, tissue or cell type is an important issue for the pathogenesis of disease. To explore the mechanistic role of viral strain variation for uterine disease, the present study aimed to develop a tool enabling precise genetic discrimination between strains of BoHV-4 and to easily manipulate the viral genome. Methods A strain of BoHV-4 was isolated from the uterus of a persistently infected cow and designated BoHV-4-U. The authenticity of the isolate was confirmed by RFLP-PCR and sequencing using the TK and IE2 loci as genetic marker regions for the BoHV-4 genome. The isolated genome was cloned as a Bacterial Artificial Chromosome (BAC) and manipulated through recombineering technology Results The BoHV-4-U genome was successfully cloned as a BAC, and the stability of the pBAC-BoHV-4-U clone was confirmed over twenty passages, with viral growth similar to the wild type virus. The feasibility of using BoHV-4-U for mutagenesis was demonstrated using the BAC recombineering system. Conclusion The analysis of genome strain variation is a key method for investigating genes associated with disease. A resource for dissection of the interactions between BoHV-4 and host endometrial cells was generated by cloning the genome of BoHV-4 as a BAC. PMID:19691825

  15. Advances in plant chromosome genomics.

    PubMed

    Doležel, Jaroslav; Vrána, Jan; Cápal, Petr; Kubaláková, Marie; Burešová, Veronika; Simková, Hana

    2014-01-01

    Next generation sequencing (NGS) is revolutionizing genomics and is providing novel insights into genome organization, evolution and function. The number of plant genomes targeted for sequencing is rising. For the moment, however, the acquisition of full genome sequences in large genome species remains difficult, largely because the short reads produced by NGS platforms are inadequate to cope with repeat-rich DNA, which forms a large part of these genomes. The problem of sequence redundancy is compounded in polyploids, which dominate the plant kingdom. An approach to overcoming some of these difficulties is to reduce the full nuclear genome to its individual chromosomes using flow-sorting. The DNA acquired in this way has proven to be suitable for many applications, including PCR-based physical mapping, in situ hybridization, forming DNA arrays, the development of DNA markers, the construction of BAC libraries and positional cloning. Coupling chromosome sorting with NGS offers opportunities for the study of genome organization at the single chromosomal level, for comparative analyses between related species and for the validation of whole genome assemblies. Apart from the primary aim of reducing the complexity of the template, taking a chromosome-based approach enables independent teams to work in parallel, each tasked with the analysis of a different chromosome(s). Given that the number of plant species tractable for chromosome sorting is increasing, the likelihood is that chromosome genomics - the marriage of cytology and genomics - will make a significant contribution to the field of plant genetics. PMID:24406816

  16. Chromosomal Flexibility

    ERIC Educational Resources Information Center

    Journal of College Science Teaching, 2005

    2005-01-01

    Scientists have shown that a genetic element on one chromosome may direct gene activity on another. Howard Hughes Medical Institute (HHMI) researchers report that a multitasking master-control region appears to over-see both a set of its own genes and a related gene on a nearby chromosome. The findings reinforce the growing importance of location…

  17. Rapid EST Isolation from Chromosome 1R of Rye

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To obtain important expressed sequence tags (ESTs) located on specific chromosomes is difficult at present. Construction of single chromosome EST library could be an efficient strategy to isolate important ESTs located on specific chromosomes. In this research, we develop a method to rapidly isola...

  18. Terminal sequence importance of de novo proteins from binary-patterned library: stable artificial proteins with 11- or 12-amino acid alphabet.

    PubMed

    Okura, Hiromichi; Takahashi, Tsuyoshi; Mihara, Hisakazu

    2012-06-01

    Successful approaches of de novo protein design suggest a great potential to create novel structural folds and to understand natural rules of protein folding. For these purposes, smaller and simpler de novo proteins have been developed. Here, we constructed smaller proteins by removing the terminal sequences from stable de novo vTAJ proteins and compared stabilities between mutant and original proteins. vTAJ proteins were screened from an α3β3 binary-patterned library which was designed with polar/ nonpolar periodicities of α-helix and β-sheet. vTAJ proteins have the additional terminal sequences due to the method of constructing the genetically repeated library sequences. By removing the parts of the sequences, we successfully obtained the stable smaller de novo protein mutants with fewer amino acid alphabets than the originals. However, these mutants showed the differences on ANS binding properties and stabilities against denaturant and pH change. The terminal sequences, which were designed just as flexible linkers not as secondary structure units, sufficiently affected these physicochemical details. This study showed implications for adjusting protein stabilities by designing N- and C-terminal sequences. PMID:22519540

  19. Meiotic Crossing over between Nonhomologous Chromosomes Affects Chromosome Segregation in Yeast

    PubMed Central

    Jinks-Robertson, S.; Sayeed, S.; Murphy, T.

    1997-01-01

    Meiotic recombination between artificial repeats positioned on nonhomologous chromosomes occurs efficiently in the yeast Saccharomyces cerevisiae. Both gene conversion and crossover events have been observed, with crossovers yielding reciprocal translocations. In the current study, 5.5-kb ura3 repeats positioned on chromosomes V and XV were used to examine the effect of ectopic recombination on meiotic chromosome segregation. Ura(+) random spores were selected and gene conversion vs. crossover events were distinguished by Southern blot analysis. Approximately 15% of the crossover events between chromosomes V and XV were associated with missegregation of one of these chromosomes. The missegregation was manifest as hyperploid spores containing either both translocations plus a normal chromosome, or both normal chromosomes plus one of the translocations. In those cases where it could be analyzed, missegregation occurred at the first meiotic division. These data are discussed in terms of a model in which ectopic crossovers compete efficiently with normal allelic crossovers in directing meiotic chromosome segregation. PMID:9136001

  20. Novel glycoside hydrolases identified by screening a Chinese Holstein dairy cow rumen-derived metagenome library.

    PubMed

    Zhao, Shengguo; Wang, Jiaqi; Bu, Dengpan; Liu, Kailang; Zhu, Yaxin; Dong, Zhiyang; Yu, Zhongtang

    2010-10-01

    One clone encoding glycoside hydrolases was identified through functional screening of a rumen bacterial artificial chromosome (BAC) library. Of the 68 open reading frames (ORFs) predicted, one ORF encodes a novel endo-β-1,4-xylanase with two catalytic domains of family GH43 and two cellulose-binding modules (CBMs) of family IV. Partial characterization showed that this endo-xylanase has a greater specific activity than a number of other xylanases over a wide temperature range at neutral pH and could be useful in some industrial applications. PMID:20709844

  1. Library Cooperation.

    ERIC Educational Resources Information Center

    Lund, Patricia; And Others

    1993-01-01

    Includes nine articles that discuss cooperative library networking in Illinois. Highlights include library systems as cooperative agencies; PALI (Private Academic Libraries of Illinois); rural school and public library development; systemwide users; regional medical libraries; virtual libraries and the Coalition for Networked Information; a…

  2. Chromosome Abnormalities

    MedlinePlus

    ... decade, newer techniques have been developed that allow scientists and doctors to screen for chromosomal abnormalities without using a microscope. These newer methods compare the patient's DNA to a normal DNA ...

  3. Original Research: Generation of non-deletional hereditary persistence of fetal hemoglobin β-globin locus yeast artificial chromosome transgenic mouse models: -175 Black HPFH and -195 Brazilian HPFH.

    PubMed

    Braghini, Carolina A; Costa, Flavia C; Fedosyuk, Halyna; Neades, Renee Y; Novikova, Lesya V; Parker, Matthew P; Winefield, Robert D; Peterson, Kenneth R

    2016-04-01

    Fetal hemoglobin is a major genetic modifier of the phenotypic heterogeneity in patients with sickle cell disease and certain β-thalassemias. Normal levels of fetal hemoglobin postnatally are approximately 1% of total hemoglobin. Patients who have hereditary persistence of fetal hemoglobin, characterized by elevated synthesis of γ-globin in adulthood, show reduced disease pathophysiology. Hereditary persistence of fetal hemoglobin is caused by β-globin locus deletions (deletional hereditary persistence of fetal hemoglobin) or γ-globin gene promoter point mutations (non-deletional hereditary persistence of fetal hemoglobin). Current research has focused on elucidating the pathways involved in the maintenance/reactivation of γ-globin in adult life. To better understand these pathways, we generated new β-globin locus yeast artificial chromosome transgenic mice bearing the (A)γ-globin -175 T > C or -195 C > G hereditary persistence of fetal hemoglobin mutations to model naturally occurring hereditary persistence of fetal hemoglobin. Adult -175 and -195 mutant β-YAC mice displayed a hereditary persistence of fetal hemoglobin phenotype, as measured at the mRNA and protein levels. The molecular basis for these phenotypes was examined by chromatin immunoprecipitation of transcription factor/co-factor binding, including YY1, PAX1, TAL1, LMO2, and LDB1. In -175 HPFH versus wild-type samples, the occupancy of LMO2, TAL1 and LDB1 proteins was enriched in HPFH mice (5.8-fold, 5.2-fold and 2.7-fold, respectively), a result that concurs with a recent study in cell lines showing that these proteins form a complex with GATA-1 to mediate long-range interactions between the locus control region and the (A)γ-globin gene. Both hereditary persistence of fetal hemoglobin mutations result in a gain of (A)γ-globin activation, in contrast to other hereditary persistence of fetal hemoglobin mutations that result in a loss of repression. The mice provide additional tools to

  4. Generation of non-deletional hereditary persistence of fetal hemoglobin β-globin locus yeast artificial chromosome transgenic mouse models: −175 Black HPFH and −195 Brazilian HPFH

    PubMed Central

    Braghini, Carolina A; Costa, Flavia C; Fedosyuk, Halyna; Neades, Renee Y; Novikova, Lesya V; Parker, Matthew P; Winefield, Robert D; Peterson, Kenneth R

    2016-01-01

    Fetal hemoglobin is a major genetic modifier of the phenotypic heterogeneity in patients with sickle cell disease and certain β-thalassemias. Normal levels of fetal hemoglobin postnatally are approximately 1% of total hemoglobin. Patients who have hereditary persistence of fetal hemoglobin, characterized by elevated synthesis of γ-globin in adulthood, show reduced disease pathophysiology. Hereditary persistence of fetal hemoglobin is caused by β-globin locus deletions (deletional hereditary persistence of fetal hemoglobin) or γ-globin gene promoter point mutations (non-deletional hereditary persistence of fetal hemoglobin). Current research has focused on elucidating the pathways involved in the maintenance/reactivation of γ-globin in adult life. To better understand these pathways, we generated new β-globin locus yeast artificial chromosome transgenic mice bearing the Aγ-globin −175 T >C or −195 C >G hereditary persistence of fetal hemoglobin mutations to model naturally occurring hereditary persistence of fetal hemoglobin. Adult −175 and −195 mutant β-YAC mice displayed a hereditary persistence of fetal hemoglobin phenotype, as measured at the mRNA and protein levels. The molecular basis for these phenotypes was examined by chromatin immunoprecipitation of transcription factor/co-factor binding, including YY1, PAX1, TAL1, LMO2, and LDB1. In −175 HPFH versus wild-type samples, the occupancy of LMO2, TAL1 and LDB1 proteins was enriched in HPFH mice (5.8-fold, 5.2-fold and 2.7-fold, respectively), a result that concurs with a recent study in cell lines showing that these proteins form a complex with GATA-1 to mediate long-range interactions between the locus control region and the Aγ-globin gene. Both hereditary persistence of fetal hemoglobin mutations result in a gain of Aγ-globin activation, in contrast to other hereditary persistence of fetal hemoglobin mutations that result in a loss of repression. The mice provide additional tools to study

  5. Multicolor FISHs for simultaneous detection of genes and DNA segments on human chromosomes.

    PubMed

    Shimizu, Nobuyoshi; Maekawa, Masahiko; Asai, Satoko; Shimizu, Yoshiko

    2015-12-01

    We have developed a convenient multicolor fluorescent in situ hybridization (FISH) (five-, four-, three-, and two-color FISHs) for detecting specific genes/DNA segments on the human chromosomes. As a foundation of multicolor FISH, we first isolated 80 bacterial artificial chromosome (BAC) probes that specifically detect the peri-centromeres (peri-CEN) and subtelomeres (subTEL) of 24 different human chromosomes (nos. 1~22, X, and Y) by screening our homemade BAC library (Keio BAC library) consisting of 200,000 clones. Five-color FISH was performed using human DNA segments specific for peri-CEN or subTEL, which were labeled with five different fluorescent dyes [7-diethylaminocoumarin (DEAC): blue, fluorescein isothiocyanate (FITC): green, rhodamine 6G (R6G): yellow, TexRed: red, and cyanine5 (Cy5): purple]. To observe FISH signals under a fluorescence microscope, five optic filters were carefully chosen to avoid overlapping fluorescence emission. Five-color FISH and four-color FISH enabled us to accurately examine the numerical anomaly of human chromosomes. Three-color FISH using two specific BAC clones, that distinguish 5' half of oncogene epidermal growth factor receptor (EGFR) from its 3' half, revealed the amplification and truncation of EGFR in EGFR-overproducing cancer cells. Moreover, two-color FISH readily detected a fusion gene in leukemia cells such as breakpoint cluster region (BCR)/Abelson murine leukemia viral oncogene homologue (ABL) on the Philadelphia (Ph') chromosome with interchromosomal translocation. Some other successful cases such as trisomy 21 of Down syndrome are presented. Potential applications of multicolor FISH will be discussed. PMID:25947045

  6. Construction of random sheared fosmid library from Chinese cabbage and its use for Brassica rapa genome sequencing project.

    PubMed

    Park, Tae-Ho; Park, Beom-Seok; Kim, Jin-A; Hong, Joon Ki; Jin, Mina; Seol, Young-Joo; Mun, Jeong-Hwan

    2011-01-01

    As a part of the Multinational Genome Sequencing Project of Brassica rapa, linkage group R9 and R3 were sequenced using a bacterial artificial chromosome (BAC) by BAC strategy. The current physical contigs are expected to cover approximately 90% euchromatins of both chromosomes. As the project progresses, BAC selection for sequence extension becomes more limited because BAC libraries are restriction enzyme-specific. To support the project, a random sheared fosmid library was constructed. The library consists of 97536 clones with average insert size of approximately 40 kb corresponding to seven genome equivalents, assuming a Chinese cabbage genome size of 550 Mb. The library was screened with primers designed at the end of sequences of nine points of scaffold gaps where BAC clones cannot be selected to extend the physical contigs. The selected positive clones were end-sequenced to check the overlap between the fosmid clones and the adjacent BAC clones. Nine fosmid clones were selected and fully sequenced. The sequences revealed two completed gap filling and seven sequence extensions, which can be used for further selection of BAC clones confirming that the fosmid library will facilitate the sequence completion of B. rapa. PMID:21338952

  7. Artificial Limbs

    MedlinePlus

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as ...

  8. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Waltz, David L.

    1982-01-01

    Describes kinds of results achieved by computer programs in artificial intelligence. Topics discussed include heuristic searches, artificial intelligence/psychology, planning program, backward chaining, learning (focusing on Winograd's blocks to explore learning strategies), concept learning, constraint propagation, language understanding…

  9. Inexpensive Multiplexed Library Preparation for Megabase-Sized Genomes

    PubMed Central

    Desai, Michael M.; Kishony, Roy

    2015-01-01

    Whole-genome sequencing has become an indispensible tool of modern biology. However, the cost of sample preparation relative to the cost of sequencing remains high, especially for small genomes where the former is dominant. Here we present a protocol for rapid and inexpensive preparation of hundreds of multiplexed genomic libraries for Illumina sequencing. By carrying out the Nextera tagmentation reaction in small volumes, replacing costly reagents with cheaper equivalents, and omitting unnecessary steps, we achieve a cost of library preparation of $8 per sample, approximately 6 times cheaper than the standard Nextera XT protocol. Furthermore, our procedure takes less than 5 hours for 96 samples. Several hundred samples can then be pooled on the same HiSeq lane via custom barcodes. Our method will be useful for re-sequencing of microbial or viral genomes, including those from evolution experiments, genetic screens, and environmental samples, as well as for other sequencing applications including large amplicon, open chromosome, artificial chromosomes, and RNA sequencing. PMID:26000737

  10. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Information Technology Quarterly, 1985

    1985-01-01

    This issue of "Information Technology Quarterly" is devoted to the theme of "Artificial Intelligence." It contains two major articles: (1) Artificial Intelligence and Law" (D. Peter O'Neill and George D. Wood); (2) "Artificial Intelligence: A Long and Winding Road" (John J. Simon, Jr.). In addition, it contains two sidebars: (1) "Calculating and…

  11. Generation of a human chromosome 18-specific YAC clone collection and mapping of 55 unique YACs by FISH and fingerprinting

    SciTech Connect

    Chang, E.; Giacalone, J.; Welch, S.; Luna, J.; Francke, U. )

    1993-08-01

    A yeast artificial chromosome (YAC) library was constructed from a somatic cell hybrid line in which the human chromosome content had been reduced by repeated subcloning to one or two copies of chromosome 18. Screening of 4700 primary yeast transformants generated 74 clones containing a YAC with a human DNA insert averaging 190 kb in size. The human YACs were localized to subregions of chromosome 18 by in situ hybridization of biotin-labeled Alu-PCR products obtained using total yeast DNA as a template. Comparisons of interspersed repetitive sequence-PCR and restriction fragment fingerprint patterns identified five sets of identical and three sets of overlapping YACs. Dual-label fluorescence in situ hybridization interphase mapping was used to determine the order of some nonoverlapping YACs. STS (sequence-tagged site) content mapping was carried out with PCR primers for 56 chromosome 18-specific markers. The identification of YACs containing four known genes - encoding the pituitary adenylate cyclase activating polypeptide (PA-CAP), the myelin basic protein (MBP), ferrochelatase (FECH), and SSAV1, an endogenous retroviral element related to the SSAV virus - provides a precise cytological map position for the respective loci. The final collection of 55 randomly isolated, unique, and regionally localized YACs (D18S107-D18S161) is distributed over the entire chromosome and collectively covers approximately 12 Mb, i.e., 16% of the estimated 77 Mb of DNA in euchromatin of chromosome 18. These YACs provide reagents for isolation of genes in these regions and represent nucleation points for the generation of STS to increase coverage of the chromosome by YAC contigs.

  12. Synthetic chromosomes.

    PubMed

    Schindler, Daniel; Waldminghaus, Torsten

    2015-11-01

    What a living organism looks like and how it works and what are its components-all this is encoded on DNA, the genetic blueprint. Consequently, the way to change an organism is to change its genetic information. Since the first pieces of recombinant DNA have been used to transform cells in the 1970s, this approach has been enormously extended. Bigger and bigger parts of the genetic information have been exchanged or added over the years. Now we are at a point where the construction of entire chromosomes becomes a reachable goal and first examples appear. This development leads to fundamental new questions, for example, about what is possible and desirable to build or what construction rules one needs to follow when building synthetic chromosomes. Here we review the recent progress in the field, discuss current challenges and speculate on the appearance of future synthetic chromosomes. PMID:26111960

  13. Chromosome and cell genetics

    SciTech Connect

    Sharma, A.K.; Sharma, A.

    1985-01-01

    This book contains 11 chapters. Some of the titles are: Chromosomes in differentiation; Chromosome axis; Nuclear and organelle split genes; Chemical mutagenesis; and Chromosome architecture and additional elements.

  14. Construction of a BAC library and identification of Dmrt1 gene of the rice field eel, Monopterus albus

    SciTech Connect

    Jang Songhun; Zhou Fang; Xia Laixin; Zhao Wei; Cheng Hanhua . E-mail: hhcheng@whu.edu.cn; Zhou Rongjia . E-mail: rjzhou@whu.edu.cn

    2006-09-22

    A bacterial artificial chromosome (BAC) library was constructed using nuclear DNA from the rice field eel (Monopterus albus). The BAC library consists of a total of 33,000 clones with an average insert size of 115 kb. Based on the rice field eel haploid genome size of 600 Mb, the BAC library is estimated to contain approximately 6.3 genome equivalents and represents 99.8% of the genome of the rice field eel. This is first BAC library constructed from this species. To estimate the possibility of isolating a specific clone, high-density colony hybridization-based library screening was performed using Dmrt1 cDNA of the rice field eel as a probe. Both library screening and PCR identification results revealed three positive BAC clones which were overlapped, and formed a contig covering the Dmrt1 gene of 195 kb. By sequence comparisons with the Dmrt1 cDNA and sequencing of first four intron-exon junctions, Dmrt1 gene of the rice field eel was predicted to contain four introns and five exons. The sizes of first and second intron are 1.5 and 2.6 kb, respectively, and the sizes of last two introns were predicted to be about 20 kb. The Dmrt1 gene structure was conserved in evolution. These results also indicate that the BAC library is a useful resource for BAC contig construction and molecular isolation of functional genes.

  15. Human genome libraries. Final progress report, February 1, 1994--August 31, 1997

    SciTech Connect

    Kao, Fa-Ten

    1998-01-01

    The goal of this program is to use a novel technology of chromosome microdissection and microcloning to construct chromosome region-specific libraries as resources for various human genome program studies. Region specific libraries have been constructed for the entire human chromosomes 2 and 18.

  16. Novel Glycoside Hydrolases Identified by Screening a Chinese Holstein Dairy Cow Rumen-Derived Metagenome Library ▿ †

    PubMed Central

    Zhao, Shengguo; Wang, Jiaqi; Bu, Dengpan; Liu, Kailang; Zhu, Yaxin; Dong, Zhiyang; Yu, Zhongtang

    2010-01-01

    One clone encoding glycoside hydrolases was identified through functional screening of a rumen bacterial artificial chromosome (BAC) library. Of the 68 open reading frames (ORFs) predicted, one ORF encodes a novel endo-β-1,4-xylanase with two catalytic domains of family GH43 and two cellulose-binding modules (CBMs) of family IV. Partial characterization showed that this endo-xylanase has a greater specific activity than a number of other xylanases over a wide temperature range at neutral pH and could be useful in some industrial applications. PMID:20709844

  17. Library 2000.

    ERIC Educational Resources Information Center

    Drake, Miriam A.

    In fall 1984, the Georgia Institute of Technology administration and library staff began planning for Library 2000, a project aimed at creating a showcase library to demonstrate the application of the latest information technology in an academic and research environment. The purposes of Library 2000 include: increasing awareness of students,…

  18. Chromosome Microarray.

    PubMed

    Anderson, Sharon

    2016-01-01

    Over the last half century, knowledge about genetics, genetic testing, and its complexity has flourished. Completion of the Human Genome Project provided a foundation upon which the accuracy of genetics, genomics, and integration of bioinformatics knowledge and testing has grown exponentially. What is lagging, however, are efforts to reach and engage nurses about this rapidly changing field. The purpose of this article is to familiarize nurses with several frequently ordered genetic tests including chromosomes and fluorescence in situ hybridization followed by a comprehensive review of chromosome microarray. It shares the complexity of microarray including how testing is performed and results analyzed. A case report demonstrates how this technology is applied in clinical practice and reveals benefits and limitations of this scientific and bioinformatics genetic technology. Clinical implications for maternal-child nurses across practice levels are discussed. PMID:27276104

  19. Chromosome Analysis

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Perceptive Scientific Instruments, Inc., provides the foundation for the Powergene line of chromosome analysis and molecular genetic instrumentation. This product employs image processing technology from NASA's Jet Propulsion Laboratory and image enhancement techniques from Johnson Space Center. Originally developed to send pictures back to earth from space probes, digital imaging techniques have been developed and refined for use in a variety of medical applications, including diagnosis of disease.

  20. Closing the gaps on human chromosome 19 revealed genes with a high density of repetitive tandemly arrayed elements.

    SciTech Connect

    Leem, Sun-Hee; Kouprina, Natalay; Grimwood, Jane; Kim, Jung-Hyun; Mullokandov, Michael; Yoon, Young-Ho; Chae, Ji-Youn; Morgan, Jenna; Lucas, Susan; Richardson, Paul; Detter, Chris; Glavina, Tijana; Rubin, Eddy; Barrett, J. Carl; Larionov, Vladimir

    2003-09-01

    The reported human genome sequence includes about 400 gaps of unknown sequence that were not found in the bacterial artificial chromosome (BAC) and cosmid libraries used for sequencing of the genome. These missing sequences correspond to {approx} 1 percent of euchromatic regions of the human genome. Gap filling is a laborious process because it relies on analysis of random clones of numerous genomic BAC or cosmid libraries. In this work we demonstrate that closing the gaps can be accelerated by a selective recombinational capture of missing chromosomal segments in yeast. The use of both methodologies allowed us to close the four remaining gaps on the human chromosome 19. Analysis of the gap sequences revealed that they contain several abnormalities that could result in instability of the sequences in microbe hosts, including large blocks of micro- and minisatellites and a high density of Alu repeats. Sequencing of the gap regions, in both BAC and YAC forms, allowed us to generate a complete sequence of four genes, including the neuronal cell signaling gene SCK1/SLI. The SCK1/SLI gene contains a record number of minisatellites, most of which are polymorphic and transmitted through meiosis following a Mendelian inheritance. In conclusion, the use of the alternative recombinational cloning system in yeast may greatly accelerate work on closing the remaining gaps in the human genome (as well as in other complex genomes) to achieve the goal of annotation of all human genes.

  1. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Smith, Linda C.; And Others

    1988-01-01

    A series of articles focuses on artificial intelligence research and development to enhance information systems and services. Topics discussed include knowledge base designs, expert system development tools, natural language processing, expert systems for reference services, and the role that artificial intelligence concepts should have in…

  2. Artificial intelligence

    SciTech Connect

    Firschein, O.

    1984-01-01

    This book presents papers on artificial intelligence. Topics considered include knowledge engineering, expert systems, applications of artificial intelligence to scientific reasoning, planning and problem solving, error recovery in robots through failure reason analysis, programming languages, natural language, speech recognition, map-guided interpretation of remotely-sensed imagery, and image understanding architectures.

  3. Artificial Intelligence.

    ERIC Educational Resources Information Center

    Thornburg, David D.

    1986-01-01

    Overview of the artificial intelligence (AI) field provides a definition; discusses past research and areas of future research; describes the design, functions, and capabilities of expert systems and the "Turing Test" for machine intelligence; and lists additional sources for information on artificial intelligence. Languages of AI are also briefly…

  4. Construction of an expressible BAC library of the unculturable insect microorganism, stink bug Plautia stali symbiont, for the search of biologically active and useful symbiont products.

    PubMed

    Kobayashi, Hideaki; Fujii-Muramatsu, Rika; Noda, Hiroaki; Takeishi, Keiichi

    2014-01-01

    While gene products and metabolites of insect symbiotic bacteria may act as useful resources for insect-microbe studies and medicinal use, it is usually difficult to obtain the insect symbionts to some extent in quantity because most of them are unculturable. In this study, the possibility of using bacterial artificial chromosome (BAC) libraries as a heterologous gene expression tool for the discovery of novel symbiont metabolites was evaluated. A BAC library was constructed from the symbiont purified from the posterior midgut cecum of the stink bug Plautia stali. The BAC library, which consisted of 513 clones with an average insert size of 41 kb, represented greater than five-fold coverage of the genome. The ability of the BAC clones to express plural genes from large-sized insert DNA in Escherichia coli was examined by the growth of BAC-transformed leu operon-deficient DH10B cells on M9 minimal medium supplemented with glucose. Two BAC clones complemented leucine deficiency in DH10B cells; the clones contained the leu operon of the symbiont chromosome. The P. stali symbiont genes introduced into the BAC vector are functional in E. coli, and these genes are expressed in an operon unit. BAC libraries can be used to generate gene product- and metabolite-libraries, facilitating to characterize potential metabolites of the P. stali symbiont. PMID:24694601

  5. Analysis of chromosome conservation in Lemur catta studied by chromosome paints and BAC/PAC probes.

    PubMed

    Cardone, Maria Francesca; Ventura, Mario; Tempesta, Sergio; Rocchi, Mariano; Archidiacono, Nicoletta

    2002-12-01

    A panel of human chromosome painting probes and bacterial and P1 artificial chromosome (BAC/PAC) clones were used in fluorescence in situ hybridization (FISH) experiments to investigate the chromosome conservation of the ring-tailed lemur (Lemur catta, LCA) with respect to human. Whole chromosome paints specific for human chromosomes 7, 9, 11, 13, 14, 17, 18, 20, 21, and X were found to identify a single chromosome or an uninterrupted chromosomal region in LCA. A large set of partial chromosome paints and BAC/PAC probes were then used to refine the characterization of the rearrangements differentiating the two karyotypes. The results were also used to reconstruct the ancestral Lemuridae karyotype. Lemur catta, indeed, can be used as an outgroup, allowing symplesiomorphic (ancestral) rearrangements to be distinguished from apomorphic (derived) rearrangements in lemurs. Some LCA chromosomes are difficult to distinguish morphologically. The 'anchorage' of most LCA chromosomes to specific probes will contribute to the standardization of the karyotype of this species. PMID:12474064

  6. Special Libraries

    ERIC Educational Resources Information Center

    Lavendel, Giuliana

    1977-01-01

    Discusses problems involved in maintaining special scientific or engineering libraries, including budget problems, remote storage locations, rental computer retrieval systems, protecting trade secrets, and establishing a magnetic tape library. (MLH)

  7. Mosaic supernumerary ring chromosome 19 identified by comparative genomic hybridisation.

    PubMed Central

    Ghaffari, S R; Boyd, E; Connor, J M; Jones, A M; Tolmie, J L

    1998-01-01

    We report the use of comparative genomic hybridisation (CGH) to define the origin of a supernumerary ring chromosome which conventional cytogenetic banding and fluorescence in situ hybridisation (FISH) methods had failed to identify. Targeted FISH using whole chromosome 19 library arm and site specific probes then confirmed the CGH results. This study shows the feasibility of using CGH for the identification of supernumerary marker chromosomes, even in fewer than 50% of cells, where no clinical or cytogenetic clues are present. Images PMID:9783708

  8. Artificial urushi.

    PubMed

    Kobayashi, S; Uyama, H; Ikeda, R

    2001-11-19

    A new concept for the design and laccase-catalyzed preparation of "artificial urushi" from new urushiol analogues is described. The curing proceeded under mild reaction conditions to produce the very hard cross-linked film (artificial urushi) with a high gloss surface. A new cross-linkable polyphenol was synthesized by oxidative polymerization of cardanol, a phenol derivative from cashew-nut-shell liquid, by enzyme-related catalysts. The polyphenol was readily cured to produce the film (also artificial urushi) showing excellent dynamic viscoelasticity. PMID:11763444

  9. Library Skills.

    ERIC Educational Resources Information Center

    Paul, Karin; Kuhlthau, Carol C.; Branch, Jennifer L.; Solowan, Diane Galloway; Case, Roland; Abilock, Debbie; Eisenberg, Michael B.; Koechlin, Carol; Zwaan, Sandi; Hughes, Sandra; Low, Ann; Litch, Margaret; Lowry, Cindy; Irvine, Linda; Stimson, Margaret; Schlarb, Irene; Wilson, Janet; Warriner, Emily; Parsons, Les; Luongo-Orlando, Katherine; Hamilton, Donald

    2003-01-01

    Includes 19 articles that address issues related to library skills and Canadian school libraries. Topics include information literacy; inquiry learning; critical thinking and electronic research; collaborative inquiry; information skills and the Big 6 approach to problem solving; student use of online databases; library skills; Internet accuracy;…

  10. Physical chromosome mapping of repetitive DNA sequences in Nile tilapia Oreochromis niloticus: evidences for a differential distribution of repetitive elements in the sex chromosomes.

    PubMed

    Ferreira, Irani A; Martins, Cesar

    2008-06-01

    Repetitive DNAs have been extensively applied as physical chromosome markers on comparative studies, identification of chromosome rearrangements and sex chromosomes, chromosome evolution analysis, and applied genetics. Here we report the characterization of repetitive DNA sequences from the Nile tilapia (Oreochromis niloticus) genome by construction and screening of plasmid library enriched with repetitive DNAs, analysis of a BAC-based physical map, and hybridization to chromosomes. The physical mapping of BACs enriched with repetitive sequences and C(o)t-1 DNA (DNA enriched for highly and moderately repetitive DNA sequences) to chromosomes using FISH showed a predominant distribution of repetitive elements in the centromeric and telomeric regions and along the entire length of the largest chromosome pair (X and Y sex chromosomes) of the species. The distribution of repetitive DNAs differed significantly between the p arm of X and Y chromosomes. These findings suggest that repetitive DNAs have had an important role in the differentiation of sex chromosomes. PMID:17395473